Geochemical Behavior of Trace Elements in Eclogites from the CCSD Main Hole during Retrograde Metamorphism
The Qingling-Dabie-Sulu orogenic belt resulted from collision between of North China Craton and Yantze Craton is the largest UHP metamorphic belt in the world. One main target of the CCSD project is to reveal the mantle-crust interaction and geochemical recycling during continental subduction and eclogite exhumation. Trace elemental compositions and variations of the eclogites and single minerals were measured to study the trace element mobility during retrograde metamorphism. Geochemical records of the origin and evolution of serpentinized peridotite from Xougou were also studied. Main conclusions made in this work are following:(1) Except for heavy rare earth elements in garnet, trace elements in eclogite are strongly distributed in favor of minor/accessory minerals compared with major minerals.
For example, Cs, Rb and Ba are largely enriched in mica, light rare earth elements in apatite, epidote and sphene, and Nb and Zr in rutile and sphene.
Alnico magnets Thus, stability of primary minerals and formations of secondary minerals affect significantly the behavior of trace elements during retrograde metamorphism, and resulted in fractionations of trace element during retrograde.(2) Studies on samples suffered from transitional retrograde metamorphism demonstrate that large ion lithophile elements and light rare earth elements show significant variations, whereas high field strength elements and heavy rare earth elements show little variations. These observations suggest that fluids associated with retrograde metamorphism were enriched in large ion lithophile elements and light rare earth elements, not enriched in high field strength elements Nb, Ta and heavy rare earth elements. Zr and Hf maybe enriched during retrograde metamorphism Depletions of high field strength elements and heavy rare earth elements in the fluids imply that the external fluids were poor in anionic complex.(3) Accessory minerals and retrograde fluids are Alnico magnets main factors controlling the trace elemental behavior during retrograde metamorphism. Formations and/or decompositions of minor/accessory minerals and chemical compositions (e.g., contents of anionic complex) of the fluids affect significantly the behavior of trace elements during retrograde metamorphism.(4) Serpentinized peridotites from Xougou were studied. Based on bulk rock chemical compositions, we suggest that the trace elements of the serpentinized peridotes were resulted from melt extraction, mantle metasomatism and serpentinization near surface. Serpentinization caused enrichments of Pb and Sr. Pb contents are positively correlated with serpentinization degree. Also Pb/Ce ratio is higher than island arc basalt and continental crust. Zr、 Hf maybe enriched in serpentinization fluid.
2012年4月27日星期五
包头稀土高新区土地管理与集约利用的创新性实践研究
包头稀土高新区土地管理与集约利用的创新性实践研究
Along with China’s reform and opening up, various economic structural reforms have been constantly deepened with the target of building up the socialist market economy Land has become one of the most important production elements in industrial construction http://www.999magnet.com/ and development, and the urban land system of China has experienced a historical change since 1980s. With the goal of realizing the market-orientated allocation of land resources, the reform of urban land usage system has been forged ahead vigorously, and as a result, the market for urban land transaction has taken into shape.
The industrial developments zones have become a special carrier for allocation of land resources, however, lots of deputes related to the efficiency of land use have been generated. As a result, the central government implemented a nationwide deflation policy Special shape NdFeB magnets on land supply in the industrial development zones in 2004, and which has been proved as an effective control to land supply.This paper starts with a general analysis on the land management and utilization of the Hi-tech Zones in China under the market-oriented economy circumstance, and the current situation of intensive utilization of land in hi-tech zones. With a focus on the Baotou Rare Earth Hi-tech Zone, the author analyzes the experiences at different stages of the development of Baotou Rare Earth Hi-tech zone, explains the contradiction between the zone’s demands of social and economic development of and the usage of land resource and the creative practices in exploitation and utilization of land resources. The paper delves into a study on land usage efficiency and allocation form of land resources. The studies Special shape NdFeB magnets and analysis shows that the allocation of land resources in Baotou Rare Earth Hi-tech Zone is of high efficiency, and which has been demonstrated in both input and output efficiency of land. Finally, from the view of satisfying the requirements of macro economic and social development, the author put forward the proposal that the land management should be brought into line with the regional economic development.
Along with China’s reform and opening up, various economic structural reforms have been constantly deepened with the target of building up the socialist market economy Land has become one of the most important production elements in industrial construction http://www.999magnet.com/ and development, and the urban land system of China has experienced a historical change since 1980s. With the goal of realizing the market-orientated allocation of land resources, the reform of urban land usage system has been forged ahead vigorously, and as a result, the market for urban land transaction has taken into shape.
The industrial developments zones have become a special carrier for allocation of land resources, however, lots of deputes related to the efficiency of land use have been generated. As a result, the central government implemented a nationwide deflation policy Special shape NdFeB magnets on land supply in the industrial development zones in 2004, and which has been proved as an effective control to land supply.This paper starts with a general analysis on the land management and utilization of the Hi-tech Zones in China under the market-oriented economy circumstance, and the current situation of intensive utilization of land in hi-tech zones. With a focus on the Baotou Rare Earth Hi-tech Zone, the author analyzes the experiences at different stages of the development of Baotou Rare Earth Hi-tech zone, explains the contradiction between the zone’s demands of social and economic development of and the usage of land resource and the creative practices in exploitation and utilization of land resources. The paper delves into a study on land usage efficiency and allocation form of land resources. The studies Special shape NdFeB magnets and analysis shows that the allocation of land resources in Baotou Rare Earth Hi-tech Zone is of high efficiency, and which has been demonstrated in both input and output efficiency of land. Finally, from the view of satisfying the requirements of macro economic and social development, the author put forward the proposal that the land management should be brought into line with the regional economic development.
Study on Preparation of Phosphate Glass-Ceramics
Study on Preparation of Phosphate Glass-Ceramics
In this work, series of P2O5-Al2O3-SiO2 (PAS) glass and rare-earth doped phosphate glass were prepared by melting-quenching method. Combined with the glass structure and crystallization properties of phosphate glass systems, compositional effects on glass thermal stability, and other properties of advanced phosphate glasses were investigated.Results indicate that 15-28mol% P2O5 can form a stable glass in PAS system. With the increase of P2O5 content, the P-O- bond become weaker and the P=O bond strengthen, which means that P5+ exists in [PO4] tetrahedron with partial P=O bond. At higher P2O5 content, the glass structure which composd by [PO4] and [SiO4] tetrahedron Alnico magnets doesn’t change.The form ability of PAS glass and non-isothermal crystallization properties were investigated by non-isothermal DSC experiment and ?atava and Ozawa-Chen method,the crystallization parameter of glass is accounted. Results indicateΔT and H·are appropriate criterion. At higher P2O5 content, the stability of PAS glass decreases.
The crystal growth factor match crystal growth pattern which observe by SEM. The best glass heat-treated system is crystallized at 670℃for 1.5h. http://www.999magnet.com/ In this work, RE2O3(RE3+=La3+、Pr3+、Sm3+、Gd3+、Er3+、Yb3+, x=0.510) doped PAS galss were prepared. The influence of rare-earth oxides on glass structure, thermal stability, category and morphology of crystal were investigated. The results indicated that rare-earth oxides act as network modifier, in the interspace of glass structure, does not change the basic glass structure,At higher RE2O3 content, the stability of PAS glass increases and the crystallization tendency decreases. With the addition of Yb2O3, the stability of the glass enhances and the activation energy E for crystallization increases when Yb2O3 content is less than 1.5wt%. Alnico magnets The stability of the sample is the best and E is the largest at 1.5wt% Yb2O3 doped, then both decrease when Yb2O3 content is over 1.5wt%. The crystal phases in P2O5-Al2O3-SiO2 glass-ceramics keep the same after Yb2O3 doped. The primary crystal phase is AlPO4 and the subordinate is Mg3(PO4)2.When Yb2O3 doped the phosphate glass crystal on the surface exist with globosity,while the other rare-earth oxides doped the phosphate glass crystal on the surface exist with acerous.When rare-earth oxides doped the phosphate glass, with the increase of CFS,TEC decreases. With the increase of rare-earth oxides molecular weight, hardness and density of phosphate glass increases.
In this work, series of P2O5-Al2O3-SiO2 (PAS) glass and rare-earth doped phosphate glass were prepared by melting-quenching method. Combined with the glass structure and crystallization properties of phosphate glass systems, compositional effects on glass thermal stability, and other properties of advanced phosphate glasses were investigated.Results indicate that 15-28mol% P2O5 can form a stable glass in PAS system. With the increase of P2O5 content, the P-O- bond become weaker and the P=O bond strengthen, which means that P5+ exists in [PO4] tetrahedron with partial P=O bond. At higher P2O5 content, the glass structure which composd by [PO4] and [SiO4] tetrahedron Alnico magnets doesn’t change.The form ability of PAS glass and non-isothermal crystallization properties were investigated by non-isothermal DSC experiment and ?atava and Ozawa-Chen method,the crystallization parameter of glass is accounted. Results indicateΔT and H·are appropriate criterion. At higher P2O5 content, the stability of PAS glass decreases.
The crystal growth factor match crystal growth pattern which observe by SEM. The best glass heat-treated system is crystallized at 670℃for 1.5h. http://www.999magnet.com/ In this work, RE2O3(RE3+=La3+、Pr3+、Sm3+、Gd3+、Er3+、Yb3+, x=0.510) doped PAS galss were prepared. The influence of rare-earth oxides on glass structure, thermal stability, category and morphology of crystal were investigated. The results indicated that rare-earth oxides act as network modifier, in the interspace of glass structure, does not change the basic glass structure,At higher RE2O3 content, the stability of PAS glass increases and the crystallization tendency decreases. With the addition of Yb2O3, the stability of the glass enhances and the activation energy E for crystallization increases when Yb2O3 content is less than 1.5wt%. Alnico magnets The stability of the sample is the best and E is the largest at 1.5wt% Yb2O3 doped, then both decrease when Yb2O3 content is over 1.5wt%. The crystal phases in P2O5-Al2O3-SiO2 glass-ceramics keep the same after Yb2O3 doped. The primary crystal phase is AlPO4 and the subordinate is Mg3(PO4)2.When Yb2O3 doped the phosphate glass crystal on the surface exist with globosity,while the other rare-earth oxides doped the phosphate glass crystal on the surface exist with acerous.When rare-earth oxides doped the phosphate glass, with the increase of CFS,TEC decreases. With the increase of rare-earth oxides molecular weight, hardness and density of phosphate glass increases.
2012年4月26日星期四
Preparation and Properties of Cathode Materials Ln1-x SrxCoO3-δ (Ln=La, Pr, Nd, Sm, Eu) Thin Film
Preparation and Properties of Cathode Materials Ln1-x SrxCoO3-δ (Ln=La, Pr, Nd, Sm, Eu) Thin Film
The superfine powder of Ln0.5Sr0.5CoO3-δ( Ln =La, Pr, Nd, Sm, Eu) which is used in the cathode material of solid oxide fuel cell (SOFC) were obtained by solid state reactions. We have studied the crystal structures and electrical transport properties when rare earth magnets doping different rare-earth elements as well as the forming process of the Perovskite structure. Then the DC conductivity of the samples at different temperature has been tested.
Then we have obtained La0.5Sr0.5CoO3-δ thin films which are on the oxidizing yttrium steady oxidizing the zirconium (YSZ) and aluminate lanthanum (LaAlO3) by ion-beam sputtering method. Studied and analyzed the surface composition micro-structures and chemical states.The results show that when the temperature reach 1200℃, the samples would become a steady and unitary Perovskite phase by solid state reactions. The conductive behavior at low temperature is consistent with small polaron mechanism. However the maximum of conductivity appears at about 700 ℃, http://www.chinamagnets.biz/ and the conductivity of La0.5Sr0.5CoO3-δis the biggest in the intermediate-temperature (600～850℃), so the electricity properties is best.The results of the XRD spectras show that the La0.5Sr0.5CoO3-δ thin films which
The superfine powder of Ln0.5Sr0.5CoO3-δ( Ln =La, Pr, Nd, Sm, Eu) which is used in the cathode material of solid oxide fuel cell (SOFC) were obtained by solid state reactions. We have studied the crystal structures and electrical transport properties when rare earth magnets doping different rare-earth elements as well as the forming process of the Perovskite structure. Then the DC conductivity of the samples at different temperature has been tested.
Then we have obtained La0.5Sr0.5CoO3-δ thin films which are on the oxidizing yttrium steady oxidizing the zirconium (YSZ) and aluminate lanthanum (LaAlO3) by ion-beam sputtering method. Studied and analyzed the surface composition micro-structures and chemical states.The results show that when the temperature reach 1200℃, the samples would become a steady and unitary Perovskite phase by solid state reactions. The conductive behavior at low temperature is consistent with small polaron mechanism. However the maximum of conductivity appears at about 700 ℃, http://www.chinamagnets.biz/ and the conductivity of La0.5Sr0.5CoO3-δis the biggest in the intermediate-temperature (600～850℃), so the electricity properties is best.The results of the XRD spectras show that the La0.5Sr0.5CoO3-δ thin films which
Research on Vibration Fault Diagnosis System of Rare-Earth Permanent Magnet Machines
Research on Vibration Fault Diagnosis System of Rare-Earth Permanent Magnet Machines
Rare-earth permanent magnet machines are used in the production of industry and agriculture no more than 30 years. It played a great role in national production, People pay more and more attention on it, but there is little research to make on fault diagnosis of rare-earth permanent magnet machines, so it is more meaningful to do a work on vibration fault diagnosis system of rare-earth permanent magnet machines.Permanent magnet machines use permanent magnet for exciting instead of electric excitation, so there is no such fault as broken rotor bar, winding short circuit, casting defects produced by large current or overload.
For this there more reliable in permanent neodymium rare earth magnets magnet machines, but there still has fault in stator such as inter-turn short circuit, layer short circuit, phase to phase short circuit and stator loosening. In this paper has been analyzed electromagnetic force wave of permanent magnet synchronous motor when it is working, and obtained the vibration characteristics of unbalance stator, paper also concluded main machinery vibration faults’ characteristic.On fault signal processing, multi-resolution analysis (MRA) based on wavelet analysis theory is put in forward in this paper to decompose fault signal from high to low frequency. The fast wavelet algorithm-Mallat pyramidal algorithm is realized by VB program and applied it to do multilevel wavelet decomposition, then compare signal processing results with FFT analysis, it proved that wavelet analysis is better than Fourier analysis in processing multilevel frequency and transient signal.Paper use improved BP neural network algorithm which theory has been fully developed and more practical to identify faults. Applied momentum neodymium rare earth magnets BP algorithm to resolve norm BP neural network algorithm has long training time and easily fall into minimization by sample data normalization and increasing momentum factor.
Combined with fault character frequency of permanent magnet synchronous motor defined input sample and output goal data. Paper identified faults by 3-layer network and optimized the number of middle layer and learning rate. Training results prove that optimized network has improved in convergence speed. Testing training results by input new fault sample show that it can identify fault sample pattern.Paper use VB program to create a diagnosis system based on wavelet analysis and BP neural network algorithm, basis on ISO2372 standards classified equipment. Applied http://www.chinamagnets.biz/ system to analyzing 55kW rare-earth permanent magnet machines used in pumping unit, proved that wavelet analysis is suit to analyzing fault signal and the results of BP diagnosis is consistent with fact.
Rare-earth permanent magnet machines are used in the production of industry and agriculture no more than 30 years. It played a great role in national production, People pay more and more attention on it, but there is little research to make on fault diagnosis of rare-earth permanent magnet machines, so it is more meaningful to do a work on vibration fault diagnosis system of rare-earth permanent magnet machines.Permanent magnet machines use permanent magnet for exciting instead of electric excitation, so there is no such fault as broken rotor bar, winding short circuit, casting defects produced by large current or overload.
For this there more reliable in permanent neodymium rare earth magnets magnet machines, but there still has fault in stator such as inter-turn short circuit, layer short circuit, phase to phase short circuit and stator loosening. In this paper has been analyzed electromagnetic force wave of permanent magnet synchronous motor when it is working, and obtained the vibration characteristics of unbalance stator, paper also concluded main machinery vibration faults’ characteristic.On fault signal processing, multi-resolution analysis (MRA) based on wavelet analysis theory is put in forward in this paper to decompose fault signal from high to low frequency. The fast wavelet algorithm-Mallat pyramidal algorithm is realized by VB program and applied it to do multilevel wavelet decomposition, then compare signal processing results with FFT analysis, it proved that wavelet analysis is better than Fourier analysis in processing multilevel frequency and transient signal.Paper use improved BP neural network algorithm which theory has been fully developed and more practical to identify faults. Applied momentum neodymium rare earth magnets BP algorithm to resolve norm BP neural network algorithm has long training time and easily fall into minimization by sample data normalization and increasing momentum factor.
Combined with fault character frequency of permanent magnet synchronous motor defined input sample and output goal data. Paper identified faults by 3-layer network and optimized the number of middle layer and learning rate. Training results prove that optimized network has improved in convergence speed. Testing training results by input new fault sample show that it can identify fault sample pattern.Paper use VB program to create a diagnosis system based on wavelet analysis and BP neural network algorithm, basis on ISO2372 standards classified equipment. Applied http://www.chinamagnets.biz/ system to analyzing 55kW rare-earth permanent magnet machines used in pumping unit, proved that wavelet analysis is suit to analyzing fault signal and the results of BP diagnosis is consistent with fact.
2012年4月24日星期二
Study on Corrosion Resistence of Al18B4O33w 6061Al Composite with Rare Earth Conversion Coating
Study on Corrosion Resistence of Al18B4O33w/6061Al Composite with Rare Earth Conversion Coating
Technological process of rare earth conversion(REC) coating on Al18B4O33w/6061Al composite was researched in this paper. The best technical parameter of conversion coating was obtained by orthogonal tests. The effects of technical parameter (concentrations of rare earth salts, concentrations of oxidizer H2O2, pH and immersion time) on the formation and corrosion properties of the coating were studied in detail. The microstructures, elements composition, and thickness of the conversion coating have been examined by scanning electron microscopy(SEM) and energy dispersive X-ray, and the corrosion behavior and corrosion mechanism of the composite with conversion coating were evaluated by polarization curves and electrochemical impedance spectroscopy(EIS).Block Neodymium magnets Various surface microstructures were observed in the composite with conversion coating. An obvious difference in morphological transformations was observed on the surfaces of the coating composites.
The surface of the sample with the optimal conversion parameter treated can be covered by the coating.XPS analysis indicated that the conversion coatings were composed of cerium oxidation and hydroxide. The main phases detected http://www.999magnet.com/ in the conversion coating were Ce3+and Ce4+, according to the characteristic peak.The results of polarization curves indicate that concentration of cerium solution has significant influences on the corrosion resistance of the conversion coating, and the optimal conversion parameter of cerium concentration was 7.5 percent. Other parameters have also significant influences on the corrosion resistance of coating. An increase in Epit was obtained after conversion treatment for the composite. The improvement was considered primarily due to Block Neodymium magnets the rare earth conversion coating inhibit the propagation of corrosion.Moreover, the specimen with the optimal conversion parameter treated exhibited a much greater resistance to corrosion than the other specimens with conversion treated. This was attributed to the formation of the homogeneous and compact microstructure in the surface of the composite.
Technological process of rare earth conversion(REC) coating on Al18B4O33w/6061Al composite was researched in this paper. The best technical parameter of conversion coating was obtained by orthogonal tests. The effects of technical parameter (concentrations of rare earth salts, concentrations of oxidizer H2O2, pH and immersion time) on the formation and corrosion properties of the coating were studied in detail. The microstructures, elements composition, and thickness of the conversion coating have been examined by scanning electron microscopy(SEM) and energy dispersive X-ray, and the corrosion behavior and corrosion mechanism of the composite with conversion coating were evaluated by polarization curves and electrochemical impedance spectroscopy(EIS).Block Neodymium magnets Various surface microstructures were observed in the composite with conversion coating. An obvious difference in morphological transformations was observed on the surfaces of the coating composites.
The surface of the sample with the optimal conversion parameter treated can be covered by the coating.XPS analysis indicated that the conversion coatings were composed of cerium oxidation and hydroxide. The main phases detected http://www.999magnet.com/ in the conversion coating were Ce3+and Ce4+, according to the characteristic peak.The results of polarization curves indicate that concentration of cerium solution has significant influences on the corrosion resistance of the conversion coating, and the optimal conversion parameter of cerium concentration was 7.5 percent. Other parameters have also significant influences on the corrosion resistance of coating. An increase in Epit was obtained after conversion treatment for the composite. The improvement was considered primarily due to Block Neodymium magnets the rare earth conversion coating inhibit the propagation of corrosion.Moreover, the specimen with the optimal conversion parameter treated exhibited a much greater resistance to corrosion than the other specimens with conversion treated. This was attributed to the formation of the homogeneous and compact microstructure in the surface of the composite.
Research of Rare-earth Cerium Conversion Film to Improve Corrosion Resistance on Stainless Steels Surface
Research of Rare-earth Cerium Conversion Film to Improve Corrosion Resistance on Stainless Steels Surface
As a traditional passivation method, chromate passivating process is a goodmethod to improve the corrosion resistance,it can also improve the surface quality andextend the service life of metals. But Cr6+ has great toxicity to both human body andenvironment. To avoid the disadvantageous influence of Cr6+, we need to replace thispassivation method. In recent years, people find out rare-earth metals, particularlywhich contain cerium salt, are effective corrosion inhibitors for aluminum, zinc, iron,magnesium, their alloys, stainless steel and carbon steel in atrocious environment. Ithas been successfully used in surface modification of various aluminum and Zn-platingsteel, but rare in the study of the stainless steel. In this paper , the improved corrosionresistance of stainless steels by rare-earth cerium conversion film were studied.(1)Research of the polishing technics of stainless steel.Special shape NdFeB magnets Based on performances of various acids in the polishing of stainless steel,polishing technics were studied.At the same time , for the sake of clean and brightsurface ,we add some the additive into the solution.(2) Stainless steel surface was dealed in the solution of both Ce2(SO4)3and H2O2.The optimum composition of the deal solution was gained by L9(34) orthogonaltest.
The best technics parameters were as follows: Ce2(SO4)3: 0.010mol/L ; H2O2:100ml/L ; deal temperature:75℃;deal time:60min.(3) Conversion film has been tested by electrochemical anodic polarization curves.The inhibit mechanism of conversion film for stainless steel anodic corrosion,analyses and compares various conversion films were discussed. The results show thatthe corrosion potential increased from 20 mV which were tested for stainless steelbefore dealing to 250～1000 mV which were tested for conversion film on the stainlesssteel surface after dealing.(4) Tested for conversion film by EIS (electrochemical impedance spectroscopy)analysis.The results show that the polarization resistance for the untreated samples was0.05MΩ·cm-2 , which it increased to values 4 MΩ·cm-2 for the samples treated forconversion film on the stainless steel surface. Therefore, the polarization resistance ofconversion film on the stainless steel surface was increased by 80 times than Special shape NdFeB magnets that onstainless steel surface. (5) SEM tested for the conversion film.The particles deposit states and surface morphology of the films were investigatedby SEM . The results show that the particles on conversion film were interveined byeach other , which covered stainless steels closely. Conversion film made corrosionvelocity slower, which was achieved by conversion film isolation between stainlesssteel and corrosion solution.(6) EDS tested for the conversion film.EDS tested in order to identify which element play the main role in theenhancement of the passivation behaviour. The results show that the http://www.999magnet.com/ cerium played animportant role in inhibition the stainless steels corrosion . How the conversion filmsperformed depended on the quantity of the cerium in them.(7) To discuss reaction mechanism of forming conversion films on stainless steel surface.Integrating the results from the experiments of SEM, EDS and XRD, it can beconcluded that conversion film was made up of iron, chromium, nickel and ceriumoxides and hydroxides.
As a traditional passivation method, chromate passivating process is a goodmethod to improve the corrosion resistance,it can also improve the surface quality andextend the service life of metals. But Cr6+ has great toxicity to both human body andenvironment. To avoid the disadvantageous influence of Cr6+, we need to replace thispassivation method. In recent years, people find out rare-earth metals, particularlywhich contain cerium salt, are effective corrosion inhibitors for aluminum, zinc, iron,magnesium, their alloys, stainless steel and carbon steel in atrocious environment. Ithas been successfully used in surface modification of various aluminum and Zn-platingsteel, but rare in the study of the stainless steel. In this paper , the improved corrosionresistance of stainless steels by rare-earth cerium conversion film were studied.(1)Research of the polishing technics of stainless steel.Special shape NdFeB magnets Based on performances of various acids in the polishing of stainless steel,polishing technics were studied.At the same time , for the sake of clean and brightsurface ,we add some the additive into the solution.(2) Stainless steel surface was dealed in the solution of both Ce2(SO4)3and H2O2.The optimum composition of the deal solution was gained by L9(34) orthogonaltest.
The best technics parameters were as follows: Ce2(SO4)3: 0.010mol/L ; H2O2:100ml/L ; deal temperature:75℃;deal time:60min.(3) Conversion film has been tested by electrochemical anodic polarization curves.The inhibit mechanism of conversion film for stainless steel anodic corrosion,analyses and compares various conversion films were discussed. The results show thatthe corrosion potential increased from 20 mV which were tested for stainless steelbefore dealing to 250～1000 mV which were tested for conversion film on the stainlesssteel surface after dealing.(4) Tested for conversion film by EIS (electrochemical impedance spectroscopy)analysis.The results show that the polarization resistance for the untreated samples was0.05MΩ·cm-2 , which it increased to values 4 MΩ·cm-2 for the samples treated forconversion film on the stainless steel surface. Therefore, the polarization resistance ofconversion film on the stainless steel surface was increased by 80 times than Special shape NdFeB magnets that onstainless steel surface. (5) SEM tested for the conversion film.The particles deposit states and surface morphology of the films were investigatedby SEM . The results show that the particles on conversion film were interveined byeach other , which covered stainless steels closely. Conversion film made corrosionvelocity slower, which was achieved by conversion film isolation between stainlesssteel and corrosion solution.(6) EDS tested for the conversion film.EDS tested in order to identify which element play the main role in theenhancement of the passivation behaviour. The results show that the http://www.999magnet.com/ cerium played animportant role in inhibition the stainless steels corrosion . How the conversion filmsperformed depended on the quantity of the cerium in them.(7) To discuss reaction mechanism of forming conversion films on stainless steel surface.Integrating the results from the experiments of SEM, EDS and XRD, it can beconcluded that conversion film was made up of iron, chromium, nickel and ceriumoxides and hydroxides.
The Development of Brazed CBN Wheel with Addition of Rare-earth in Brazing Alloy
The Development of Brazed CBN Wheel with Addition of Rare-earth in Brazing Alloy
There are several distinguished properties in Cubic boron nitride (CBN) abrasive, such as extremely high hardness, superior thermal stability, large chemical inertia and excellent thermal conductivity. CBN wheels have been utilized widely and good effects were found in grinding difficult-to-machine materials like titanium alloy. The most extensive and steadily used in the brazing of CBN grain was Ag-Cu-Ti alloy, it’s working temperature can not exceed 600℃though Magnetic lifter good performance in brazing joint can be gained in room temperature. Rare earth element can improve the activity of the exterior in grain while the percentage of Ti in the brazing alloy at a lower level, these caused enough interface chemical reaction and moisten effect between brazing alloy and grain. Furthermore, the addition of certain RE (Rare earth) with certain percentage can keep the sharpness of the abrasive.
These provided excellent grinding performance in titanium alloy grinding using RE additional brazed CBN wheel.The main contents in this paper are as follows:(1) Explore the brazing process which can provide substance jointing among RE additional brazed alloy、CBN abrasive and steel, discovered that 0.5 wt% La can get the most favorite brazing quality;(2) Grinding force Magnetic lifter comparable experiments were measured using two integral type mono-layer brazed CBN. Evaluate the grinding ability of the two wheels by tracing the surface quality http://www.999magnet.com/ under certain material removal;(3) Design and fabricate the interrupted type mono-layer brazed CBN wheel according to the requirements of titanium alloy component with complex contour, to exert the potential of this new type tool by the application in the profile grinding of titanium alloy.
There are several distinguished properties in Cubic boron nitride (CBN) abrasive, such as extremely high hardness, superior thermal stability, large chemical inertia and excellent thermal conductivity. CBN wheels have been utilized widely and good effects were found in grinding difficult-to-machine materials like titanium alloy. The most extensive and steadily used in the brazing of CBN grain was Ag-Cu-Ti alloy, it’s working temperature can not exceed 600℃though Magnetic lifter good performance in brazing joint can be gained in room temperature. Rare earth element can improve the activity of the exterior in grain while the percentage of Ti in the brazing alloy at a lower level, these caused enough interface chemical reaction and moisten effect between brazing alloy and grain. Furthermore, the addition of certain RE (Rare earth) with certain percentage can keep the sharpness of the abrasive.
These provided excellent grinding performance in titanium alloy grinding using RE additional brazed CBN wheel.The main contents in this paper are as follows:(1) Explore the brazing process which can provide substance jointing among RE additional brazed alloy、CBN abrasive and steel, discovered that 0.5 wt% La can get the most favorite brazing quality;(2) Grinding force Magnetic lifter comparable experiments were measured using two integral type mono-layer brazed CBN. Evaluate the grinding ability of the two wheels by tracing the surface quality http://www.999magnet.com/ under certain material removal;(3) Design and fabricate the interrupted type mono-layer brazed CBN wheel according to the requirements of titanium alloy component with complex contour, to exert the potential of this new type tool by the application in the profile grinding of titanium alloy.
2012年4月22日星期日
Research on the Application of Pack Boronizing in Petroleum Machinery
Research on the Application of Pack Boronizing in Petroleum Machinery
Some parts of petroleum machinery work under severe conditions. The conditions involve hard particles such as grit and corrosion mediums such as H2S、HCO3- so that these parts must be wearable and corrosion-resistant. Because of the high hardness of the borided layer and its fine wear resistant, oxidation-resistant in high temperature and corrosion-resistant capacity, the boronizing technology has been used widely. Because of simple to operate and easy to clean, pack boronizing has received extensive attention in recent years. Extending the application of Alnico magnets pack boronizing can improve the quality and prolong the life of petroleum machinery parts. Therefore, it is necessary and practically meaningful to research the application of pack boronizing in petroleum machinery.However, pack boronizing has some disadvantages. For example, high temperature and long time is required when boronizing. Due to distinct brittleness, easily-craze and easily-spall liability of borided layer, the mechanical properties of the substrate are debased and the wear resistant and corrosion-resistant properties are affected. These restrain further development and application of pack boronizing. In the present work, the microstructure, mechanical properties, friction and wear properties and corrosion resistant properties of the boronizing samples of sucker tube and sucker rod joint were studied by using different heat treatment methods and adding rare earth compound in boriding agent. All of these will offer theoretical and practical foundations for extending applications of pack boronizing in petroleum machinery.Alnico magnets Under the condition of boronizing, the borided layer of 36Mn2V steel is composed of FeB phase and Fe2B phase.
The amount of pearlite increases, whereas the amount of ferrite decreases with the increasing of cooling velocity. As the cooling velocity increases, the mechanical properties are remarkably improved. The fan-cooled sample with graphite bar inside has the highest ultimate strength and yield strength. Fractography analysis indicates that the fractured surface of tested 36Mn2V steel samples at room temperature has many ductile dimples and tearing ridges. All of the fractured surfaces accord with typical ductile fracture feature.The microstructures of 36Mn2V steel which is boronized with lanthanum chloride mixed rare earth and 45 steel which is boronized with neodymium oxide rare earth were studied. The results demonstrate that with the increasing rare earth content, FeB phase reduces and Fe2B phase increases. Rare earth has a catalytic effect on borided layer. The content of rare earth added has an optimized range; the thickness of borided layer will decrease with excessive content of rare earth.Carbon content of 45 steel which is boronized with neodymium oxide rare earth increases from the layer to the transition zone, and it reaches a maximum in the transition zone. The fracture toughness values of FeB and Fe2B phases are higher than that of boronized sample. The brittleness of borided layer reduces.In the present work, friction and wear resistance of boronized and RE-boronized samples were studied. The results indicate that the wear rate of boronized 36Mn2V steel increases with the increasing of test loads, whereas the friction coefficient decreases. The samples of 36Mn2V steel which is boronized with lanthanum chloride mixed rare earth were given the test load of 130N. The wear rate of the samples with less lanthanum chloride mixed rare earth is lower than that of boronized samples. The friction coefficient of the samples increases with increasing content of rare earth.
The wear rate of boronized 45 steel and 45 steel which is boronized with 3% neodymium oxide rare earth increases with the increasing of tested loads and the friction coefficient decreases. Under the condition of high test loads, the wear rate of RE-boronized samples Alnico magnets is relative lower than that of boronized samples. The analysis of worn surfaces reveals that the wear mechanism of boronized and RE-boronized samples is abrasive wear.The corrosion resistance of the boronizing samples was studied. The test results show that the corrosion resistance of boronized 36Mn2V steel is remarkably improved than that of non-borided samples. The corrosion potential of 36Mn2V steel which boronized with lanthanum chloride mixed rare earth is higher than that of boronized and non-borided samples, and the corrosion resistance of RE-boronized samples is improved.The analysis of dynamics reveals that the thickness of borided layer of boronized 45 steel and T12 steel increases with the increasing of boronized temperature. At the same temperature, the thickness of borided layer http://www.999magnet.com/ decreases with the increasing of carbon content. The calculated values of activation energies for the boronizing process in the 45 and T12 steels are about 184kJ/mol and 261kJ/mol, respectively.
Some parts of petroleum machinery work under severe conditions. The conditions involve hard particles such as grit and corrosion mediums such as H2S、HCO3- so that these parts must be wearable and corrosion-resistant. Because of the high hardness of the borided layer and its fine wear resistant, oxidation-resistant in high temperature and corrosion-resistant capacity, the boronizing technology has been used widely. Because of simple to operate and easy to clean, pack boronizing has received extensive attention in recent years. Extending the application of Alnico magnets pack boronizing can improve the quality and prolong the life of petroleum machinery parts. Therefore, it is necessary and practically meaningful to research the application of pack boronizing in petroleum machinery.However, pack boronizing has some disadvantages. For example, high temperature and long time is required when boronizing. Due to distinct brittleness, easily-craze and easily-spall liability of borided layer, the mechanical properties of the substrate are debased and the wear resistant and corrosion-resistant properties are affected. These restrain further development and application of pack boronizing. In the present work, the microstructure, mechanical properties, friction and wear properties and corrosion resistant properties of the boronizing samples of sucker tube and sucker rod joint were studied by using different heat treatment methods and adding rare earth compound in boriding agent. All of these will offer theoretical and practical foundations for extending applications of pack boronizing in petroleum machinery.Alnico magnets Under the condition of boronizing, the borided layer of 36Mn2V steel is composed of FeB phase and Fe2B phase.
The amount of pearlite increases, whereas the amount of ferrite decreases with the increasing of cooling velocity. As the cooling velocity increases, the mechanical properties are remarkably improved. The fan-cooled sample with graphite bar inside has the highest ultimate strength and yield strength. Fractography analysis indicates that the fractured surface of tested 36Mn2V steel samples at room temperature has many ductile dimples and tearing ridges. All of the fractured surfaces accord with typical ductile fracture feature.The microstructures of 36Mn2V steel which is boronized with lanthanum chloride mixed rare earth and 45 steel which is boronized with neodymium oxide rare earth were studied. The results demonstrate that with the increasing rare earth content, FeB phase reduces and Fe2B phase increases. Rare earth has a catalytic effect on borided layer. The content of rare earth added has an optimized range; the thickness of borided layer will decrease with excessive content of rare earth.Carbon content of 45 steel which is boronized with neodymium oxide rare earth increases from the layer to the transition zone, and it reaches a maximum in the transition zone. The fracture toughness values of FeB and Fe2B phases are higher than that of boronized sample. The brittleness of borided layer reduces.In the present work, friction and wear resistance of boronized and RE-boronized samples were studied. The results indicate that the wear rate of boronized 36Mn2V steel increases with the increasing of test loads, whereas the friction coefficient decreases. The samples of 36Mn2V steel which is boronized with lanthanum chloride mixed rare earth were given the test load of 130N. The wear rate of the samples with less lanthanum chloride mixed rare earth is lower than that of boronized samples. The friction coefficient of the samples increases with increasing content of rare earth.
The wear rate of boronized 45 steel and 45 steel which is boronized with 3% neodymium oxide rare earth increases with the increasing of tested loads and the friction coefficient decreases. Under the condition of high test loads, the wear rate of RE-boronized samples Alnico magnets is relative lower than that of boronized samples. The analysis of worn surfaces reveals that the wear mechanism of boronized and RE-boronized samples is abrasive wear.The corrosion resistance of the boronizing samples was studied. The test results show that the corrosion resistance of boronized 36Mn2V steel is remarkably improved than that of non-borided samples. The corrosion potential of 36Mn2V steel which boronized with lanthanum chloride mixed rare earth is higher than that of boronized and non-borided samples, and the corrosion resistance of RE-boronized samples is improved.The analysis of dynamics reveals that the thickness of borided layer of boronized 45 steel and T12 steel increases with the increasing of boronized temperature. At the same temperature, the thickness of borided layer http://www.999magnet.com/ decreases with the increasing of carbon content. The calculated values of activation energies for the boronizing process in the 45 and T12 steels are about 184kJ/mol and 261kJ/mol, respectively.
Synthesis and Photoluminescence Properties of Rare Earth Doped Phosphate and Fluoride Nanoparticles Prepared in a Microreactor Systerm
Synthesis and Photoluminescence Properties of Rare Earth Doped Phosphate and Fluoride Nanoparticles Prepared in a Microreactor Systerm
In the field of fluorescent biological labeling,semiconductor nanocrystals have heavy metallic toxicity and fluorescent light flashing,so rare earth doped luminous nanoparticles have attracted many attentions.However,little reliable method,which can prepare redispersible rare earth doped nanoparticles with narrow particle size distribution and high luminescent properties at the present time was reported.Recently microreaction technology is expected to have a number of advantages for synthesis of nanoparticles,such as feasibility for controlling the experimental condition exactly, possibility for optimizing reaction parameter fastly,and scale up easily.Microreactor technology has shown the application value for preparing nanoparticles. In this paper,current study on Magnetic lifter luminescence nano-materials used for biological labeling,the rare earth doped materials and the microreactor technology had been reviewed.The luminescence mechanics,the preparation methods of rare earth materials were introduced.The parameters of microreactor,such as the mixing of microfluids,the mass transfer between microfluids and the heat transfer of microfluids had been studied.
The microreactor which can rapidly mix two kinds of reaction microfluids and effectively controlled the reaction time had been made up.The CePO4:Tb,LaPO4:Eu,LaPO4:Ce,Tb nanocrystals were prepared in ethylene alcohol by a microreactor,and their phase structure,morphology and fuorescence property were characterized by X-ray diffraction spectra(XRD),transmission electron microscope(TEM)and photoluminescence(PL).The results of XRD indicate that nanoparticles crystallized well with a hexagonal structure.The TEM images illustrate that the LaPO4:Ce,Tb nanoparticles prepared in a microreactor with 5s reaction time had the main diameter of below 20nm and were well dispersible.The results of PL indicate that Ce0.70PO4:Tb0.30,La0.90PO4:Eu0.10, La0.70PO4:Ce0.20,Tb0.10nanoparticles with high fluorescent properties can be prepared in a microreactor with low Magnetic lifter reaction temperature of 80℃and short reaction time of 20s,and the quantum yields of these nanoparticles can reach 22%,25%,24%respectively.In order to improve the product rate of nanoparticles prepared in a microreactor, two kind of heating methods microwave and oil http://www.999magnet.com/ bath were used to prepare nanoparticles.The results illustrate that microwave obviously improve the productive rate which can achieve more than 90%.
The CeF3:Tb,LaF3:Ce,Tb nanocrystals were prepared in ethylene alcohol by a microreactor,and their phase structure, morphology and fluorescence property were characterized by X-ray diffraction spectra(XRD),transmission electron microscope(TEM) and photoluminescence(PL).The results of XRD indicate that nanoparticles crystallized well with a hexagonal structure.The TEM images illustrate that nanoparticles are nearly spherical with diameter of 5-10nm,and have homogeneous size distribution,well dispersibility.The results of PL indicate that Ce0.80F3:Tb0.20 nanoparticles with high fluorescent property can be prepared in a microreactor with low reaction temperature of 80℃and short reaction time of 20s,and the quantum yield of nanoparticles can reach 32%.The results of a simple Magnetic lifter fluorescent labeling indicate that the most rare earth luminous nanoparticles(Ce0.80F3:Tb0.20)can come into lung cell.The luminous nanoparticles can be distinctly seen under the fluorescent microscope.Above results show that rare earth doped nanoparticles in a microreactor have the possibility for using in the field of biological labeling.
In the field of fluorescent biological labeling,semiconductor nanocrystals have heavy metallic toxicity and fluorescent light flashing,so rare earth doped luminous nanoparticles have attracted many attentions.However,little reliable method,which can prepare redispersible rare earth doped nanoparticles with narrow particle size distribution and high luminescent properties at the present time was reported.Recently microreaction technology is expected to have a number of advantages for synthesis of nanoparticles,such as feasibility for controlling the experimental condition exactly, possibility for optimizing reaction parameter fastly,and scale up easily.Microreactor technology has shown the application value for preparing nanoparticles. In this paper,current study on Magnetic lifter luminescence nano-materials used for biological labeling,the rare earth doped materials and the microreactor technology had been reviewed.The luminescence mechanics,the preparation methods of rare earth materials were introduced.The parameters of microreactor,such as the mixing of microfluids,the mass transfer between microfluids and the heat transfer of microfluids had been studied.
The microreactor which can rapidly mix two kinds of reaction microfluids and effectively controlled the reaction time had been made up.The CePO4:Tb,LaPO4:Eu,LaPO4:Ce,Tb nanocrystals were prepared in ethylene alcohol by a microreactor,and their phase structure,morphology and fuorescence property were characterized by X-ray diffraction spectra(XRD),transmission electron microscope(TEM)and photoluminescence(PL).The results of XRD indicate that nanoparticles crystallized well with a hexagonal structure.The TEM images illustrate that the LaPO4:Ce,Tb nanoparticles prepared in a microreactor with 5s reaction time had the main diameter of below 20nm and were well dispersible.The results of PL indicate that Ce0.70PO4:Tb0.30,La0.90PO4:Eu0.10, La0.70PO4:Ce0.20,Tb0.10nanoparticles with high fluorescent properties can be prepared in a microreactor with low Magnetic lifter reaction temperature of 80℃and short reaction time of 20s,and the quantum yields of these nanoparticles can reach 22%,25%,24%respectively.In order to improve the product rate of nanoparticles prepared in a microreactor, two kind of heating methods microwave and oil http://www.999magnet.com/ bath were used to prepare nanoparticles.The results illustrate that microwave obviously improve the productive rate which can achieve more than 90%.
The CeF3:Tb,LaF3:Ce,Tb nanocrystals were prepared in ethylene alcohol by a microreactor,and their phase structure, morphology and fluorescence property were characterized by X-ray diffraction spectra(XRD),transmission electron microscope(TEM) and photoluminescence(PL).The results of XRD indicate that nanoparticles crystallized well with a hexagonal structure.The TEM images illustrate that nanoparticles are nearly spherical with diameter of 5-10nm,and have homogeneous size distribution,well dispersibility.The results of PL indicate that Ce0.80F3:Tb0.20 nanoparticles with high fluorescent property can be prepared in a microreactor with low reaction temperature of 80℃and short reaction time of 20s,and the quantum yield of nanoparticles can reach 32%.The results of a simple Magnetic lifter fluorescent labeling indicate that the most rare earth luminous nanoparticles(Ce0.80F3:Tb0.20)can come into lung cell.The luminous nanoparticles can be distinctly seen under the fluorescent microscope.Above results show that rare earth doped nanoparticles in a microreactor have the possibility for using in the field of biological labeling.
Effect of Rare Earth Nd, Y and Gd on Microstructure and High Temperature Mechanical Properties of AZ Magnesium Alloys
Effect of Rare Earth Nd, Y and Gd on Microstructure and High Temperature Mechanical Properties of AZ Magnesium Alloys
As the lightest structural metallic materials, magnesium alloys have high specificstrength, high specific stiffness, excellent electro-magnetic shielding ability and heatdispersion, good processing properties and casting properties. Therefore, magnesiumalloys have been extensively applied in automotive, communication and aircraftindusties. However, its lower strength and creep resistance at elevated temperaturecause the poor heat resistance of magnesium alloy, which is the main factor of limitingits application at elevated temperature.In this thesis, the effects of different rare earth Nd, Y and Gd on themicrostructure and high-temperature mechanical properties of AZ91 and AZS1magnesium alloy were studied by using optical microstructure(OM), x-raydiffraction(XRD), scan electric microscopy (SEM)/energy dispersive spectrometer(EDS) and tensile properties test.The results show that, rare earth elements effectively refine grains of AZ91 andAZ81 magnesium alloy, increase Neodymium Magnets room temperature mechanical properties and hightemperature mechanical properties, and improve ductility of alloys. For AZ91 alloywith 1%～4%Nd, with the increase of Nd, the tensile strength of alloy rise at first andthen drop.
When the content of Nd is 1%, the tensile strength of alloy reach itsmaximum value at room temperature and 150℃, 247.8MPa and 203.1MParespectively, 10.7% and 29.3% higher than AZ91 without Nd. When the content of Ndis 2%, the elongation of alloy reach maximum at 150℃and 250℃, 10.5% and 13.7%respectively.Rare earth Nd, Y and Gd also can refine the grain of AZ81 magnesium alloy. ForAZ81 alloy with 1%～4%Y, with the increase of Y, the tensile strength and elongationof AZ81 magnesium alloy rise at first and then drop. http://www.999magnet.com/ At room temperature, when thecontent of Y is 2%, the tensile strength and the elongation of alloy reach the maximum value, and the peak value are 277.1MPa and 10.9% respectively. Its room temperaturemechanical is 36.5% higher than AZ81 without Y. At 150~C, when the content of Y is1%, the tensile strength and the elongation of alloy reach maximum value, and thepeak value are 220.7MPa and 12.4% respectively. Its high temperature mechanical is40.1% higher than AZ81 alloy’s. For AZ81 alloy with Gd, at room temperature and150℃, the Neodymium Magnets tensile strength of alloy reach maximum value, and the peak value are280.1MPa and 212.7MPa when the content of Gd is 3%, respectively. The elongationis best when the content of Gd is 2%～3%. For AZ81 alloy with Nd and Y(Nd/Y=2:3),the tensile strength of alloy reach maximum value, and the peak value are 282.5MPaand 212.2MPa at room temperature and 150℃when the content of Nd and Y is 2%,respectively, and the elongation is also best.It is considered that rare earth Nd, Y and Gd can effectively improves the tensilestrength and ductility of AZ91 and AZ81 magnesium alloy due to the effects of solid-solution strengthening, precipitation strengthening and fine-grained strengthening.
As the lightest structural metallic materials, magnesium alloys have high specificstrength, high specific stiffness, excellent electro-magnetic shielding ability and heatdispersion, good processing properties and casting properties. Therefore, magnesiumalloys have been extensively applied in automotive, communication and aircraftindusties. However, its lower strength and creep resistance at elevated temperaturecause the poor heat resistance of magnesium alloy, which is the main factor of limitingits application at elevated temperature.In this thesis, the effects of different rare earth Nd, Y and Gd on themicrostructure and high-temperature mechanical properties of AZ91 and AZS1magnesium alloy were studied by using optical microstructure(OM), x-raydiffraction(XRD), scan electric microscopy (SEM)/energy dispersive spectrometer(EDS) and tensile properties test.The results show that, rare earth elements effectively refine grains of AZ91 andAZ81 magnesium alloy, increase Neodymium Magnets room temperature mechanical properties and hightemperature mechanical properties, and improve ductility of alloys. For AZ91 alloywith 1%～4%Nd, with the increase of Nd, the tensile strength of alloy rise at first andthen drop.
When the content of Nd is 1%, the tensile strength of alloy reach itsmaximum value at room temperature and 150℃, 247.8MPa and 203.1MParespectively, 10.7% and 29.3% higher than AZ91 without Nd. When the content of Ndis 2%, the elongation of alloy reach maximum at 150℃and 250℃, 10.5% and 13.7%respectively.Rare earth Nd, Y and Gd also can refine the grain of AZ81 magnesium alloy. ForAZ81 alloy with 1%～4%Y, with the increase of Y, the tensile strength and elongationof AZ81 magnesium alloy rise at first and then drop. http://www.999magnet.com/ At room temperature, when thecontent of Y is 2%, the tensile strength and the elongation of alloy reach the maximum value, and the peak value are 277.1MPa and 10.9% respectively. Its room temperaturemechanical is 36.5% higher than AZ81 without Y. At 150~C, when the content of Y is1%, the tensile strength and the elongation of alloy reach maximum value, and thepeak value are 220.7MPa and 12.4% respectively. Its high temperature mechanical is40.1% higher than AZ81 alloy’s. For AZ81 alloy with Gd, at room temperature and150℃, the Neodymium Magnets tensile strength of alloy reach maximum value, and the peak value are280.1MPa and 212.7MPa when the content of Gd is 3%, respectively. The elongationis best when the content of Gd is 2%～3%. For AZ81 alloy with Nd and Y(Nd/Y=2:3),the tensile strength of alloy reach maximum value, and the peak value are 282.5MPaand 212.2MPa at room temperature and 150℃when the content of Nd and Y is 2%,respectively, and the elongation is also best.It is considered that rare earth Nd, Y and Gd can effectively improves the tensilestrength and ductility of AZ91 and AZ81 magnesium alloy due to the effects of solid-solution strengthening, precipitation strengthening and fine-grained strengthening.
The Effects of Rare Earth La, Ce on Tin Brass’s Structure and Performance
The Effects of Rare Earth La, Ce on Tin Brass’s Structure and Performance
Because of cage shoe’s poor wear,and bad toughness,increases maintennance and overhaul for the cage, and cage shoe to be replaced frequently ,which raises security incipient fault ,resulting in increased costs of mining economy. The rare-earth elements are "the Vitamin" of metal materials; they have special functions in improving metal materials. In this paper,by strong magnets adding rare earth lanthanum, cerium to copper alloy,study http://www.chinamagnets.biz/ the mechanism of rare earth to cage shoe and the influence of rare earth on cast structure, mechanical properties and wear resistance.
The research showed that the addition of rare earth, the mechanical properties of the alloys have different effects. Lanthanum, cerium amount of 0.06% and strong magnets 0.04% respectively, showed excellent mechanical properties and wear resistance. Meanwhile, the casting process improvement, the segregation problem getting a better solution.
Because of cage shoe’s poor wear,and bad toughness,increases maintennance and overhaul for the cage, and cage shoe to be replaced frequently ,which raises security incipient fault ,resulting in increased costs of mining economy. The rare-earth elements are "the Vitamin" of metal materials; they have special functions in improving metal materials. In this paper,by strong magnets adding rare earth lanthanum, cerium to copper alloy,study http://www.chinamagnets.biz/ the mechanism of rare earth to cage shoe and the influence of rare earth on cast structure, mechanical properties and wear resistance.
The research showed that the addition of rare earth, the mechanical properties of the alloys have different effects. Lanthanum, cerium amount of 0.06% and strong magnets 0.04% respectively, showed excellent mechanical properties and wear resistance. Meanwhile, the casting process improvement, the segregation problem getting a better solution.
Influence of Rare-Earth on Microstructures and Properties of AZ61 Magnesium Alloy
Influence of Rare-Earth on Microstructures and Properties of AZ61 Magnesium Alloy
In this paper, the microstructures and tensile properties of as-cast and solution treated AZ61 magnesium alloys with and without the addition of Ce and Y, as well as as-cast AZ61 magnesium with Nd, were investigated. Moreover, the microstructures and tensile properties of the AZ61+Nd magnesium alloy subjected to hot extrusion were also studied. The ultimate tensile strength σb, 0.2% offset yield strength σ0.2 and elongation to failure 8 of the above-mentioned magnesium alloys with different chemical composition and processing statuses at different test temperatures were determined.
The evolution in the microstructure of the AZ61, AZ61+Ce, AZ61+Nd and AZ61+Y magnesium alloys due to either solution treatment and hot extrusion was discussed. And the influence of both solution treatment and hot extrusion on the tensile properties of rare earth magnets the AZ61 magnesium alloys with various contents of Ce, Y and Nd at different test temperatures were evaluated.The research results showed that with the addition of rare-earth element Nd in the AZ61 magnesium alloy, the microstructure of the as-cast alloy could be refined, where the microstructural refinement in the AZ61 alloy with 1.5% Nd was the most considerable. The addition of Nd in the AZ61 magnesium alloy could slightly increase the ultimate tensile and yield strengths of the alloy under the cast status while the elongation of the alloy could be significantly improved. After the hot extrusion, the tensile properties of the AZ61+Nd alloy could be greatly enhanced. Adding rare- earth element Ce in the AZ61 rare earth magnets magnesium alloy could also refine the microstructure of the alloy under the cast status. At the same time, for the cast AZ61 alloy, the addition of Ce could improve the yield strength at room temperature as well as the tensile properties at the higher test temperatures.
The ultimate tensile and yield http://www.chinamagnets.biz/ strengths of various AZ61+Ce alloys subjected to the solution treatment would decrease, but were higher than those of the AZ61 alloy subjected to the same heat treatment. For most of the AZ61+Ce alloys, however, the elongation was lower than that of the AZ61 after solution treatment. With an addition of the rare-earth element Y, the microstructure of the cast alloys could also be refined. Although adding Y in the AZ61 alloy had no significant influence on the yield strength at different test temperatures as well as the ultimate tensile strength at room rare earth magnets temperature, it could enhance the ultimate tensilestrength of the cast alloy at the higher test temperatures. After the solution treatment, both elongation at room temperature and yield strength at the higher test temperatures could get increased for various AZ61+Y alloys compared with the solution treated AZ61 alloy.
In this paper, the microstructures and tensile properties of as-cast and solution treated AZ61 magnesium alloys with and without the addition of Ce and Y, as well as as-cast AZ61 magnesium with Nd, were investigated. Moreover, the microstructures and tensile properties of the AZ61+Nd magnesium alloy subjected to hot extrusion were also studied. The ultimate tensile strength σb, 0.2% offset yield strength σ0.2 and elongation to failure 8 of the above-mentioned magnesium alloys with different chemical composition and processing statuses at different test temperatures were determined.
The evolution in the microstructure of the AZ61, AZ61+Ce, AZ61+Nd and AZ61+Y magnesium alloys due to either solution treatment and hot extrusion was discussed. And the influence of both solution treatment and hot extrusion on the tensile properties of rare earth magnets the AZ61 magnesium alloys with various contents of Ce, Y and Nd at different test temperatures were evaluated.The research results showed that with the addition of rare-earth element Nd in the AZ61 magnesium alloy, the microstructure of the as-cast alloy could be refined, where the microstructural refinement in the AZ61 alloy with 1.5% Nd was the most considerable. The addition of Nd in the AZ61 magnesium alloy could slightly increase the ultimate tensile and yield strengths of the alloy under the cast status while the elongation of the alloy could be significantly improved. After the hot extrusion, the tensile properties of the AZ61+Nd alloy could be greatly enhanced. Adding rare- earth element Ce in the AZ61 rare earth magnets magnesium alloy could also refine the microstructure of the alloy under the cast status. At the same time, for the cast AZ61 alloy, the addition of Ce could improve the yield strength at room temperature as well as the tensile properties at the higher test temperatures.
The ultimate tensile and yield http://www.chinamagnets.biz/ strengths of various AZ61+Ce alloys subjected to the solution treatment would decrease, but were higher than those of the AZ61 alloy subjected to the same heat treatment. For most of the AZ61+Ce alloys, however, the elongation was lower than that of the AZ61 after solution treatment. With an addition of the rare-earth element Y, the microstructure of the cast alloys could also be refined. Although adding Y in the AZ61 alloy had no significant influence on the yield strength at different test temperatures as well as the ultimate tensile strength at room rare earth magnets temperature, it could enhance the ultimate tensilestrength of the cast alloy at the higher test temperatures. After the solution treatment, both elongation at room temperature and yield strength at the higher test temperatures could get increased for various AZ61+Y alloys compared with the solution treated AZ61 alloy.
The Study on the Role of the Rare Earth and the Phosphorus in the Steel
The Study on the Role of the Rare Earth and the Phosphorus in the Steel
Most of China’s cargo transport through the rail.Heavy rail steel is the key materials;the performance will directly affect the safety of transport.Heavy rail steel,the properties are high carbon content,high alloy elements,high requirements with the wear-resistance and yield strength.The rail with RE(BNbRE) is the new product with the use of Baotou Rare-earth resource and the international advanced technologies,with the help of CHINA ACADEMY OF RAILWAY SCIENCES and other relevant departments to make.it past the standard of Ministry of Railways and the Department Ring neodymium magnet of the metallurgical technical..large number of the rails have been tested,at present,the product is the main product for the heavy load,high speed track.As the most important components of the track structure,rail need to bear long-term and greater impact of alternating load,wear and fatigue is the main failure of the rail.If a rail brittle fracture appear in the train running,it will be serious results for the rail.not only ensuring the strength,wear resistance and anti-fatigue properties,but also it http://www.chinamagnets.biz/ must ensure that the rail has good toughness and plastic.
On the study of the role of Rare Earth in the heavy rail,for promoting the increased of toughness and plastic,is of great significance.In this essay,with the use of Metallographic Microscopes,X-ray Diffraction,Scanning Electron Microscopy,Micro-hardness,Transmission Electron Microscopy,Universal Tensile test Machine Detection Apparatus,we study the sample of phosphorus iron ,we found that in the pure iron,Ce-phosphorus accumulation are easy to enrich on Ring neodymium magnet the grain sector. we systemly study the role of rare earth elements La ,Ce in the heavy rail steel of microstructure and mechanical Impact properties.through experiments and analysis,we found that in heavy rail steel,sample with cerium and phosphorus are common elements in the segregation within the inclusion,Ce-phosphorus and the segregation of phosphorus influence the mechanical properties of steel by changing the particle size and pearlite-spacing.on the whole,the increase of Ce,phosphorus and rare earth elements,the fall of mechanical properties of steel.
Most of China’s cargo transport through the rail.Heavy rail steel is the key materials;the performance will directly affect the safety of transport.Heavy rail steel,the properties are high carbon content,high alloy elements,high requirements with the wear-resistance and yield strength.The rail with RE(BNbRE) is the new product with the use of Baotou Rare-earth resource and the international advanced technologies,with the help of CHINA ACADEMY OF RAILWAY SCIENCES and other relevant departments to make.it past the standard of Ministry of Railways and the Department Ring neodymium magnet of the metallurgical technical..large number of the rails have been tested,at present,the product is the main product for the heavy load,high speed track.As the most important components of the track structure,rail need to bear long-term and greater impact of alternating load,wear and fatigue is the main failure of the rail.If a rail brittle fracture appear in the train running,it will be serious results for the rail.not only ensuring the strength,wear resistance and anti-fatigue properties,but also it http://www.chinamagnets.biz/ must ensure that the rail has good toughness and plastic.
On the study of the role of Rare Earth in the heavy rail,for promoting the increased of toughness and plastic,is of great significance.In this essay,with the use of Metallographic Microscopes,X-ray Diffraction,Scanning Electron Microscopy,Micro-hardness,Transmission Electron Microscopy,Universal Tensile test Machine Detection Apparatus,we study the sample of phosphorus iron ,we found that in the pure iron,Ce-phosphorus accumulation are easy to enrich on Ring neodymium magnet the grain sector. we systemly study the role of rare earth elements La ,Ce in the heavy rail steel of microstructure and mechanical Impact properties.through experiments and analysis,we found that in heavy rail steel,sample with cerium and phosphorus are common elements in the segregation within the inclusion,Ce-phosphorus and the segregation of phosphorus influence the mechanical properties of steel by changing the particle size and pearlite-spacing.on the whole,the increase of Ce,phosphorus and rare earth elements,the fall of mechanical properties of steel.
Synthesis、Characterization and Fluorescence Properties of Rare Earth Perchlorate with Bis(Benzoylmethyl) Sulfoxide
Synthesis、Characterization and Fluorescence Properties of Rare Earth Perchlorate with Bis(Benzoylmethyl) Sulfoxide
Twelve solid complexes of rare earth perchlorate with bis(benzoylmethyl) sulfoxide (L) and twelve-different proportional mixed complexes (Tb3+ mixed by Tm3+, Eu3+ mixed by Pr3+) of rare earth perchlorate with the ligand (L) have been synthesized and characterized. By elemental analysis, coordination titration and TGA-DSC studies, the composition of the complexes were suggested as REL5(ClO4)3·3H2O(RE=Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb; L=C6H5CO CH2SOCH2COC6H5) and (TbxTmy)L5(ClO4)3·3H2O (x:y=0.999:0.001, 0.995:0.005, 0.990:0.010, 0.950:0.050, 0.900:0.100, 0.800:0.200, 0.700:0.300; L=C6H5COCH2SO CH2COC6H5) and (EuxPry) L5 (ClO4)3·3H2O(x:y=0.999:0.001, 0.995:0.005, 0.990: 0.010, 0.950:0.050, 0.900:0.100, 0.800:0.200; L=C6H5COCH2SOCH2COC6H5). IR spectra and Cube neodymium magnet 1HNMR spectra studies indicated that bis(benzoylmethyl) sulfoxide (L) bonded with RE3+ ions by the oxygen atom in sulfinyl group while the oxygen atom in carbonyl group did not.
The molar conductivities in acetone solution indicated that two of three inorganic anions ClO4-are coordinated with RE3+. The change of melting points and decomposition points of complexes with the atomic number is serrated. All the complexes have good thermal stability. The fluorescence spectra illustrate that all of the Eu3+, Tb3+ and Dy3+ complexes display characteristic metal-centered fluorescence in solid state. Phosphorescent http://www.chinamagnets.biz/ spectrum of ligand and fluorescent decay curve of complexes showed that the triplet state of ligand is higher than 5D0 excited state of europium ion and 5D4 excited state of terbium ion. So the ligand can transfer energy to them. At the same time, after rare earth complexes being generated, the configuration of 4f-4f transition forbiddance are released, consequently the rare earth ions not only have increased fluorescence intensity, but also have long fluorescence Cube neodymium magnet lifetime. Comparing the fluorescent spectrum of the simple complexes with those of mixed coordination compounds, one can find that the thulium ions and praseodymium ions have a sensitization effect to the fluorescence of Tb3+ and Eu3+ complexes. And sensitization effect is the strongest when the ratio of Tb3+:Tm3+=0.950:0.050 and Eu3+:Pr3+=0.995:0.005, the fluorescence intensity can be increased to 208% and 110%.
Twelve solid complexes of rare earth perchlorate with bis(benzoylmethyl) sulfoxide (L) and twelve-different proportional mixed complexes (Tb3+ mixed by Tm3+, Eu3+ mixed by Pr3+) of rare earth perchlorate with the ligand (L) have been synthesized and characterized. By elemental analysis, coordination titration and TGA-DSC studies, the composition of the complexes were suggested as REL5(ClO4)3·3H2O(RE=Y, La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb; L=C6H5CO CH2SOCH2COC6H5) and (TbxTmy)L5(ClO4)3·3H2O (x:y=0.999:0.001, 0.995:0.005, 0.990:0.010, 0.950:0.050, 0.900:0.100, 0.800:0.200, 0.700:0.300; L=C6H5COCH2SO CH2COC6H5) and (EuxPry) L5 (ClO4)3·3H2O(x:y=0.999:0.001, 0.995:0.005, 0.990: 0.010, 0.950:0.050, 0.900:0.100, 0.800:0.200; L=C6H5COCH2SOCH2COC6H5). IR spectra and Cube neodymium magnet 1HNMR spectra studies indicated that bis(benzoylmethyl) sulfoxide (L) bonded with RE3+ ions by the oxygen atom in sulfinyl group while the oxygen atom in carbonyl group did not.
The molar conductivities in acetone solution indicated that two of three inorganic anions ClO4-are coordinated with RE3+. The change of melting points and decomposition points of complexes with the atomic number is serrated. All the complexes have good thermal stability. The fluorescence spectra illustrate that all of the Eu3+, Tb3+ and Dy3+ complexes display characteristic metal-centered fluorescence in solid state. Phosphorescent http://www.chinamagnets.biz/ spectrum of ligand and fluorescent decay curve of complexes showed that the triplet state of ligand is higher than 5D0 excited state of europium ion and 5D4 excited state of terbium ion. So the ligand can transfer energy to them. At the same time, after rare earth complexes being generated, the configuration of 4f-4f transition forbiddance are released, consequently the rare earth ions not only have increased fluorescence intensity, but also have long fluorescence Cube neodymium magnet lifetime. Comparing the fluorescent spectrum of the simple complexes with those of mixed coordination compounds, one can find that the thulium ions and praseodymium ions have a sensitization effect to the fluorescence of Tb3+ and Eu3+ complexes. And sensitization effect is the strongest when the ratio of Tb3+:Tm3+=0.950:0.050 and Eu3+:Pr3+=0.995:0.005, the fluorescence intensity can be increased to 208% and 110%.
2012年4月16日星期一
Sythesis, Characterization and Studies on Fluorescence Property of Rare Earth with 2, 4, 6-tri(2-pyridyl)-1, 3, 5-triazine Complexes
Sythesis, Characterization and Studies on Fluorescence Property of Rare Earth with 2, 4, 6-tri(2-pyridyl)-1, 3, 5-triazine Complexes
Four solid complexes of rare earth perchloride with 2,4,6-tri(2-pyridyl)-1,3,5-triazine, fifteen solid complexes of rare earth chloride and 2,4,6-tri(2-pyridyl)-1,3,5-triazine and four solid complexes of rare earth chloride with 2,4,6-tri(2-pyridyl)-1,3,5-triazine and benzoic acid, have been synthesized and characterazied. By elemental analysis, rare earth coordination titration and TG-DTA studies, the composition of the complexes were suggested as Re(TPTZ)2·(ClO4)3(Re=Eu, Tb, Sm, Dy) , Re(TPTZ)Cl3·3H2O and Re(C6H5COO)3(TPTZ).4H2O (Re=Eu, Tb, Sm, Dy) respectively. The molar conductivity indicates, one of the inorganic anions ClO4- is coordinated with Re3+ in the complexes of Re(TPTZ)2·(ClO4)3, two of the chloride anions Cl- are coordinated rare earth magnets with Re3+ in the complexes of Re(TPTZ)Cl3·3H2O and the complexes of Re(C6H5COO)3(TPTZ).4H2O are nonelectrolyte. IR spectra and 1HNMR spectra show that the TPTZ through the N atoms and C6H5COO- through oxygen atoms coordinate with Re3+ ions, respectively.
Fluorescence spectra and fluor- escence http://www.chinamagnets.biz/ lifetimes show that the fluorescent intensity and lifetime of terbium complexes are higher than the other complexes in Re(TPTZ)2·(ClO4)3 complexes and Re(TPTZ)Cl3·3H2O complexes, it suggests that the triplet state level of TPTZ with the excited state level of Tb3+ match well; The fluorescent intensity and lifetime ofeuropium complex is higher than the other complexes in Re(C6H5COO)3(TPTZ). 4H2O complexes, it suggests that the triplet state level of benzoic acid with the excited state level of Eu3+ match well each other, the energy, rare earth magnets which was absorbed by benzoic acid ligand, could be transferred to rare earth ions effectively. In addition, the influence of ligands and co-doped ions have also been discussed deeply. The crystal structures of Eu(C6H5COO)3(TPTZ)(H2O), [Tb(TPTZ) (H2O)6]·Cl3 and [Tb0.1Gd0.9 (TPTZ)(H2O)6]·Cl3 were successfully determined by X-ray single crystal diffraction, the crystal of Eu(C6H5COO)3(TPTZ)(H2O) is triclinic,p-1 space group andthe coordination number is 9; [Tb(TPTZ)(H2O)6]·Cl3 and [Tb0.1Gd0.9 (TPTZ)(H2O)6]·Cl3 are all monoclinic, Cc space group, coordination number is 9, respectively.
Four solid complexes of rare earth perchloride with 2,4,6-tri(2-pyridyl)-1,3,5-triazine, fifteen solid complexes of rare earth chloride and 2,4,6-tri(2-pyridyl)-1,3,5-triazine and four solid complexes of rare earth chloride with 2,4,6-tri(2-pyridyl)-1,3,5-triazine and benzoic acid, have been synthesized and characterazied. By elemental analysis, rare earth coordination titration and TG-DTA studies, the composition of the complexes were suggested as Re(TPTZ)2·(ClO4)3(Re=Eu, Tb, Sm, Dy) , Re(TPTZ)Cl3·3H2O and Re(C6H5COO)3(TPTZ).4H2O (Re=Eu, Tb, Sm, Dy) respectively. The molar conductivity indicates, one of the inorganic anions ClO4- is coordinated with Re3+ in the complexes of Re(TPTZ)2·(ClO4)3, two of the chloride anions Cl- are coordinated rare earth magnets with Re3+ in the complexes of Re(TPTZ)Cl3·3H2O and the complexes of Re(C6H5COO)3(TPTZ).4H2O are nonelectrolyte. IR spectra and 1HNMR spectra show that the TPTZ through the N atoms and C6H5COO- through oxygen atoms coordinate with Re3+ ions, respectively.
Fluorescence spectra and fluor- escence http://www.chinamagnets.biz/ lifetimes show that the fluorescent intensity and lifetime of terbium complexes are higher than the other complexes in Re(TPTZ)2·(ClO4)3 complexes and Re(TPTZ)Cl3·3H2O complexes, it suggests that the triplet state level of TPTZ with the excited state level of Tb3+ match well; The fluorescent intensity and lifetime ofeuropium complex is higher than the other complexes in Re(C6H5COO)3(TPTZ). 4H2O complexes, it suggests that the triplet state level of benzoic acid with the excited state level of Eu3+ match well each other, the energy, rare earth magnets which was absorbed by benzoic acid ligand, could be transferred to rare earth ions effectively. In addition, the influence of ligands and co-doped ions have also been discussed deeply. The crystal structures of Eu(C6H5COO)3(TPTZ)(H2O), [Tb(TPTZ) (H2O)6]·Cl3 and [Tb0.1Gd0.9 (TPTZ)(H2O)6]·Cl3 were successfully determined by X-ray single crystal diffraction, the crystal of Eu(C6H5COO)3(TPTZ)(H2O) is triclinic,p-1 space group andthe coordination number is 9; [Tb(TPTZ)(H2O)6]·Cl3 and [Tb0.1Gd0.9 (TPTZ)(H2O)6]·Cl3 are all monoclinic, Cc space group, coordination number is 9, respectively.
Research of Mg2Si/Al-20%Si In-Situ Composites and Complex Modifier
Research of Mg2Si/Al-20%Si In-Situ Composites and Complex Modifier
Mg2Si reinforced hypereutectic Al-Si alloy in-situ composites have the lower expanding and density behavior, the higher resistance to wear and corrosion and Ring neodymium magnet excellent conduct. But before appropriate modification and heat treatment, the size of Mg2Si larger, it will reduce the mechanical and machining properties due to its brittleness and the dissevering effect to the matrix. So the hypereutectic Al-Si alloy can’t been widely applied because of those disadvantages. Based on the size of Si and Mg2Si in Al-10%Mg-20%Si alloy with different types modifier, we found a new modifier:Ln2O3 + CaCO3 , and gives the good experimental craft parameter.
Then use those modified the hypereutectic Al-Si alloy with different Mg contents, Finally, researched the microstructure and properties of Al-Mg-Si alloy under compound modification and T6 heat treatment.Analysis Microstructure we found: the Ring neodymium magnet size of primary Mg2Si reduced from about 75μm to below 25μm, and the shape rules, uniform distribution. The better modification parameters is:the modifier adding quality is 0.5wt.% of the total amount of alloy(Ln2O3 is 0.2%,CaCO3 is 0.3%);modification time is 10min;modification temperature is 820℃. With the increase of Mg content, modifier also increased. The Al-10%Mg-20Si modified with Ln2O3 + CaCO3 and then T6 heat treatment, the degree of dispersion further intensify. Most of the microstructure size under 10μm. And the mechanical capability improved rapidly.In this article, the innovation point is that a new compound modification (Ln2O3 + CaCO3) has been found, and the result notable.
Mg2Si reinforced hypereutectic Al-Si alloy in-situ composites have the lower expanding and density behavior, the higher resistance to wear and corrosion and Ring neodymium magnet excellent conduct. But before appropriate modification and heat treatment, the size of Mg2Si larger, it will reduce the mechanical and machining properties due to its brittleness and the dissevering effect to the matrix. So the hypereutectic Al-Si alloy can’t been widely applied because of those disadvantages. Based on the size of Si and Mg2Si in Al-10%Mg-20%Si alloy with different types modifier, we found a new modifier:Ln2O3 + CaCO3 , and gives the good experimental craft parameter.
Then use those modified the hypereutectic Al-Si alloy with different Mg contents, Finally, researched the microstructure and properties of Al-Mg-Si alloy under compound modification and T6 heat treatment.Analysis Microstructure we found: the Ring neodymium magnet size of primary Mg2Si reduced from about 75μm to below 25μm, and the shape rules, uniform distribution. The better modification parameters is:the modifier adding quality is 0.5wt.% of the total amount of alloy(Ln2O3 is 0.2%,CaCO3 is 0.3%);modification time is 10min;modification temperature is 820℃. With the increase of Mg content, modifier also increased. The Al-10%Mg-20Si modified with Ln2O3 + CaCO3 and then T6 heat treatment, the degree of dispersion further intensify. Most of the microstructure size under 10μm. And the mechanical capability improved rapidly.In this article, the innovation point is that a new compound modification (Ln2O3 + CaCO3) has been found, and the result notable.
The Modified Research of Corrosion Resistance’s Epoxy Powder Dope
The Modified Research of Corrosion Resistance’s Epoxy Powder Dope
Although have many features such as no solvent, pollution-free and high-recovery and utilization ratio, the powder dope is mainly used in decorated field in our country. Recently, several corrosion resistant powder dope developed by domestic researcher, but the property and the quality can’t satisfy the demands of corrosion and prevention field obviously. The powder dope used to the corrosion resistance especially heavy corrosion resistance and special circumstance need to develop immediately. This thesis researched the basal prescription of epoxy powder dope, then attained preferable corrosion resistance property as well as the preferable mechanical and reserved property Cube neodymium magnet through the modifying of the powder dope.
The detailed work was as follow:1. We analysed ingredients’ dosage the means of the positive intersection experiment and then found the basal prescription of powder dope. 2. The solidifying temperature couldn’t be debased distinctly if added the solidifying agent only. In the DSC chart the preliminary temperature reduce from 160℃to 80℃. The solidifying accelerant can improve the solidifying speed obviously and the mechanical property keeps constantly.3. The bakelite are added to the epoxy system to improve the property, and the result shows the water resistance, the acid resistance are improved apparently. Furthermore, this paper also discuss the http://www.chinamagnets.biz/ cured mechanism ordinarily.4. The lanthanide is added to the epoxy system to reparation the brittleness of the dope. The investigation of IR, DSC, GPC shows that the water resistance, the corrosion resistance, the stockpiling property and mechanical strength are improved apparently.
Although have many features such as no solvent, pollution-free and high-recovery and utilization ratio, the powder dope is mainly used in decorated field in our country. Recently, several corrosion resistant powder dope developed by domestic researcher, but the property and the quality can’t satisfy the demands of corrosion and prevention field obviously. The powder dope used to the corrosion resistance especially heavy corrosion resistance and special circumstance need to develop immediately. This thesis researched the basal prescription of epoxy powder dope, then attained preferable corrosion resistance property as well as the preferable mechanical and reserved property Cube neodymium magnet through the modifying of the powder dope.
The detailed work was as follow:1. We analysed ingredients’ dosage the means of the positive intersection experiment and then found the basal prescription of powder dope. 2. The solidifying temperature couldn’t be debased distinctly if added the solidifying agent only. In the DSC chart the preliminary temperature reduce from 160℃to 80℃. The solidifying accelerant can improve the solidifying speed obviously and the mechanical property keeps constantly.3. The bakelite are added to the epoxy system to improve the property, and the result shows the water resistance, the acid resistance are improved apparently. Furthermore, this paper also discuss the http://www.chinamagnets.biz/ cured mechanism ordinarily.4. The lanthanide is added to the epoxy system to reparation the brittleness of the dope. The investigation of IR, DSC, GPC shows that the water resistance, the corrosion resistance, the stockpiling property and mechanical strength are improved apparently.
2012年4月12日星期四
题名:(Y,Gd)_2O_3:Eu~(3+)纳米粉体的制备及发光性能研究
作者:郭易芬
学位授予单位:沈阳大学
关键词:(Y,Gd)_2O_3:Eu~(3+)纳米粉体;;共沉淀;;XRD衍射技术;;显微结构;;光学性能
摘要:
(Y,Gd)_2O_3:Eu~(3+)是一种新型的闪烁陶瓷材料,具有立方晶体结构,密度为5.92g/cm~3,相对光产出为70%,衰减时间大于1×10~(-3)s,余辉小于0.01%,是一种高效率的X射线发光材料,其广泛地应用于光致发光、阴极射线发光、X射线发光等领域。近年来,(Y,Gd)_2O_3:Eu~(3+)粉体经特殊烧结制备成透明陶瓷作为X射线的探测材料得到了人们广泛的关注,但是制备优良的超细粉体材料一直是新材料研究领域需要解决的问题。本文研究了(Y,Gd)_2O_3:Eu~(3+)纳米粉体材料的制备技术,用XRD、TG/DSC、FTIR、SEM、TEM、PL等测试手段分别对超细粉体的合成、显微组织及发光性能进行了系统的研究。
以氨水为沉淀剂,研究了不同的滴定方式(正,反向),pH值,滴定速率,稀土溶液的浓度,体系温度,时效时间,煅烧温度和分散剂对超细粉体形貌及粒径的影响;讨论了激发光谱;并研究了分散剂含量,激发光波长及Eu~(3+)含量对粉体样品发射光谱的影响。研究表明:在0.15mol/L的稀土溶液中添加3%的(NH_4)_2SO_4,体系温度为0℃,2ml/min正向滴定,直至pH值为8.3,停止滴定,先驱沉淀物实效12h,经干燥后,在弱还原气氛下于800℃煅烧2h,可制备出分散性好、无团聚、一次粒径为25nm的(Y,Gd)_2O_3:Eu~(3+)纳米粉体。在612nm光监控下,(Y,Gd)_2O_3:Eu~(3+)纳米粒子产生235和250nm两个激发光谱,用这两种波长光激发时,其发射光谱强度前者高于后者。当Eu~(3+)的摩尔含量为5%时,发射光谱中的~5D_0→~7F_2跃迁态上的发射峰强最高;当Eu~(3+)的摩尔含量高于5%时出现了浓度猝灭。掺杂少量的(NH_4)_2SO_4能改变XRD衍射峰和发射峰的相对强度,但样品的相结构未发生变化。添加3wt%(NH_4)_2SO_4后制备的(Y,Gd)_2O_3:Eu~(3+)纳米粉体发射光谱的强度最佳。在碳酸氢铵为沉淀剂的实验中,研究了干燥温度,煅烧温度和Eu~(3+)含量对粉体性能的影响。研究表明:先驱沉淀物于150℃干燥时不存在任何杂质,800℃煅烧2h,粉体具有最优的分散性,且近球形,一次粒径约15nm。当掺入Eu~(3+)低于5mol%,发射光谱强度随着Eu~(3+)的含量增加而升高,含量为5mol%时,发光强度最高,超过5%使出现了浓度猝灭。用碳酸氢铵为沉淀剂比氨水为沉淀剂制备的超细粉体的分散性更好,粒径尺寸细小,发射光谱峰强度优于后者。
学位年度:2009
作者:郭易芬
学位授予单位:沈阳大学
关键词:(Y,Gd)_2O_3:Eu~(3+)纳米粉体;;共沉淀;;XRD衍射技术;;显微结构;;光学性能
摘要:
(Y,Gd)_2O_3:Eu~(3+)是一种新型的闪烁陶瓷材料,具有立方晶体结构,密度为5.92g/cm~3,相对光产出为70%,衰减时间大于1×10~(-3)s,余辉小于0.01%,是一种高效率的X射线发光材料,其广泛地应用于光致发光、阴极射线发光、X射线发光等领域。近年来,(Y,Gd)_2O_3:Eu~(3+)粉体经特殊烧结制备成透明陶瓷作为X射线的探测材料得到了人们广泛的关注,但是制备优良的超细粉体材料一直是新材料研究领域需要解决的问题。本文研究了(Y,Gd)_2O_3:Eu~(3+)纳米粉体材料的制备技术,用XRD、TG/DSC、FTIR、SEM、TEM、PL等测试手段分别对超细粉体的合成、显微组织及发光性能进行了系统的研究。
以氨水为沉淀剂,研究了不同的滴定方式(正,反向),pH值,滴定速率,稀土溶液的浓度,体系温度,时效时间,煅烧温度和分散剂对超细粉体形貌及粒径的影响;讨论了激发光谱;并研究了分散剂含量,激发光波长及Eu~(3+)含量对粉体样品发射光谱的影响。研究表明:在0.15mol/L的稀土溶液中添加3%的(NH_4)_2SO_4,体系温度为0℃,2ml/min正向滴定,直至pH值为8.3,停止滴定,先驱沉淀物实效12h,经干燥后,在弱还原气氛下于800℃煅烧2h,可制备出分散性好、无团聚、一次粒径为25nm的(Y,Gd)_2O_3:Eu~(3+)纳米粉体。在612nm光监控下,(Y,Gd)_2O_3:Eu~(3+)纳米粒子产生235和250nm两个激发光谱,用这两种波长光激发时,其发射光谱强度前者高于后者。当Eu~(3+)的摩尔含量为5%时,发射光谱中的~5D_0→~7F_2跃迁态上的发射峰强最高;当Eu~(3+)的摩尔含量高于5%时出现了浓度猝灭。掺杂少量的(NH_4)_2SO_4能改变XRD衍射峰和发射峰的相对强度,但样品的相结构未发生变化。添加3wt%(NH_4)_2SO_4后制备的(Y,Gd)_2O_3:Eu~(3+)纳米粉体发射光谱的强度最佳。在碳酸氢铵为沉淀剂的实验中,研究了干燥温度,煅烧温度和Eu~(3+)含量对粉体性能的影响。研究表明:先驱沉淀物于150℃干燥时不存在任何杂质,800℃煅烧2h,粉体具有最优的分散性,且近球形,一次粒径约15nm。当掺入Eu~(3+)低于5mol%,发射光谱强度随着Eu~(3+)的含量增加而升高,含量为5mol%时,发光强度最高,超过5%使出现了浓度猝灭。用碳酸氢铵为沉淀剂比氨水为沉淀剂制备的超细粉体的分散性更好,粒径尺寸细小,发射光谱峰强度优于后者。
学位年度:2009
石嘴山双纪煤田煤的煤岩和微量元素特征对比研究
题名:石嘴山双纪煤田煤的煤岩和微量元素特征对比研究
作者:李昶
学位授予单位:安徽理工大学
关键词:石嘴山;;双纪煤田;;煤岩学;;微量元素;;对比研究;;地质成因
摘要:
西北侏罗纪的煤炭资源丰富、煤质优良,同时开发和研究程度很低,加之现有的煤地质学理论主要是对华北石炭-二叠纪煤的研究,在这样的背景下,加强对西北侏罗纪煤的研究对于丰富煤地质学理论和促进西北煤炭资源的开发利用具有理论意义和潜在的实践价值。石嘴山煤田是包括侏罗纪和石炭-二叠纪的双纪煤田,具有研究的代表性。本文以此为对象,对煤的煤岩和微量元素特征进行对比研究,并对其地质成因Block neodymium magnet做初步探讨。
本文的分析和研究表明:汝箕沟侏罗纪煤系是湖泊河流相沉积,煤变质类型认为是热液热水变质作用,石炭井石炭纪煤系属于海陆交互相沉积,煤变质类型是深成变质作用。汝箕沟煤为无烟煤坚硬,层理较难辨别;不能区分壳质组,镜质组和惰质组的区别比较困难;石炭井焦煤硬度较软,层理清楚;壳质http://www.chinamagnets.biz/组辨别困难,镜质组和惰质组基本上能区别出来。汝箕沟无烟煤低灰、特低硫、高发热量,煤质优良;石炭井焦煤中高灰、低硫、较高的发热量。
通过煤的低温灰化样品的XRD和扫描电镜能谱分析表明,汝箕沟样品以高岭石为主,伊利石、石英为辅,黄铁矿极少或未见,而石炭井样品以高岭石占绝对优势,含较少的黄铁矿。采用INAA分析煤中的微量元素,表明汝箕沟煤的微量元素中,Se、Mo两个元素的含量偏高,石炭井煤的微量元素中Se非常富集,其它Zr、Mo、Sb、Hf、W、Th、U元素的含量偏高;石炭井煤海陆交互相的沉积环境是煤中Se和S含量高于汝箕沟煤的原因,同时海陆交互相的陆源碎屑补给多导致石炭井Zr等元素含量高。汝箕沟煤样和石炭井煤样的稀土元素分配模式、参数δEu、δCe没有明显差异,但稀土元素含量差异显著,认为这也Block neodymium magnet是由于陆源碎屑补给多造成石炭井煤样的∑REE高。
在以上对比研究的基础上,对形成这些显著差异的地质原因进行了初步分析,认为:成煤植物特征和湖泊相沉积环境可能是导致了侏罗纪煤质优良的重要原因,而汝箕沟无烟煤被认为是热水热液变质作用造成的。
学位年度:2009
作者:李昶
学位授予单位:安徽理工大学
关键词:石嘴山;;双纪煤田;;煤岩学;;微量元素;;对比研究;;地质成因
摘要:
西北侏罗纪的煤炭资源丰富、煤质优良,同时开发和研究程度很低,加之现有的煤地质学理论主要是对华北石炭-二叠纪煤的研究,在这样的背景下,加强对西北侏罗纪煤的研究对于丰富煤地质学理论和促进西北煤炭资源的开发利用具有理论意义和潜在的实践价值。石嘴山煤田是包括侏罗纪和石炭-二叠纪的双纪煤田,具有研究的代表性。本文以此为对象,对煤的煤岩和微量元素特征进行对比研究,并对其地质成因Block neodymium magnet做初步探讨。
本文的分析和研究表明:汝箕沟侏罗纪煤系是湖泊河流相沉积,煤变质类型认为是热液热水变质作用,石炭井石炭纪煤系属于海陆交互相沉积,煤变质类型是深成变质作用。汝箕沟煤为无烟煤坚硬,层理较难辨别;不能区分壳质组,镜质组和惰质组的区别比较困难;石炭井焦煤硬度较软,层理清楚;壳质http://www.chinamagnets.biz/组辨别困难,镜质组和惰质组基本上能区别出来。汝箕沟无烟煤低灰、特低硫、高发热量,煤质优良;石炭井焦煤中高灰、低硫、较高的发热量。
通过煤的低温灰化样品的XRD和扫描电镜能谱分析表明,汝箕沟样品以高岭石为主,伊利石、石英为辅,黄铁矿极少或未见,而石炭井样品以高岭石占绝对优势,含较少的黄铁矿。采用INAA分析煤中的微量元素,表明汝箕沟煤的微量元素中,Se、Mo两个元素的含量偏高,石炭井煤的微量元素中Se非常富集,其它Zr、Mo、Sb、Hf、W、Th、U元素的含量偏高;石炭井煤海陆交互相的沉积环境是煤中Se和S含量高于汝箕沟煤的原因,同时海陆交互相的陆源碎屑补给多导致石炭井Zr等元素含量高。汝箕沟煤样和石炭井煤样的稀土元素分配模式、参数δEu、δCe没有明显差异,但稀土元素含量差异显著,认为这也Block neodymium magnet是由于陆源碎屑补给多造成石炭井煤样的∑REE高。
在以上对比研究的基础上,对形成这些显著差异的地质原因进行了初步分析,认为:成煤植物特征和湖泊相沉积环境可能是导致了侏罗纪煤质优良的重要原因,而汝箕沟无烟煤被认为是热水热液变质作用造成的。
学位年度:2009
柔性有机硅树脂的合成及改性
题名:柔性有机硅树脂的合成及改性
作者:刘雷
学位授予单位:山东大学
关键词:线型聚硅氧烷;;柔性甲基苯基硅树脂;;有机硅改性环氧树脂;;光性能有机硅材料
摘要:
作为有机硅产品的重要组成部分,有机硅树脂兼有无机和有机材料的双重性能,是不同于一般有机树脂的特种高分子材料。
通常所用硅树脂虽然具有硬度高、耐磨、绝缘性能好等优点,但弹性欠佳,作为涂层材料在高、低温交变条件下有时会开裂,使其Cylinder neodymium magnet应用受到限制。为了解决这一问题,本论文开展了柔性硅树脂的研究,提出了合成柔性硅树脂的方法,并对其性能进行了改进。
本论文的研究主要分为四部分:
第一部分对硅树脂、线型聚硅氧烷、有机硅改性环氧树脂的合成方法、性能研究、应用进行了综述,为开展研究奠定了理论基础。
第二部分介绍柔性甲基苯基硅树脂的制备。本章从线型聚硅氧烷的合成入手,在偶联剂的作用下,将线型聚硅氧烷引入苯基氯硅烷水解物,制备了基体柔性有机硅树脂。探讨了聚硅氧烷的分子量、用量、偶联剂种类、固化剂http://www.chinamagnets.biz/种类等因素对树脂柔性的影响。并研究了溶剂用量、反应温度、原料配比、合成工艺等对树脂性能的影响。合成了柔性小于3mm并且耐温性达到300℃的有机硅树脂。
第三部分介绍有机硅改性环氧树脂的制备。本章首先以聚酰胺-650为偶联剂,两种线型聚硅氧烷为柔性链段,对环氧树脂TDE-85、双酚A型E-51进行了柔性改进,讨论了聚硅氧烷的分子量、用量等因素对环氧树脂性能的影响。以制备的柔性有机硅树脂为基体,通过引入适量的环氧树脂对其进行性能了改进,讨论了环氧树脂的用量、固化剂的种类、合成工艺对改性树脂柔韧性、剪切性能、耐温性能的影响。合成了柔性为3-4mm、耐温性在300-400℃的改性有机硅环氧树脂。
第四部分是一种新型光性能有机硅材料的研究。本章通过硅氢加成反应,制备了一种功能化的含酯基聚硅氧烷,通过与Eu和Tb两种稀Cylinder neodymium magnet土金属离子配位,制备出了具有红绿荧光性能的材料。详细表征了此种光性能材料的结构和光、热性能,对其在丙烯酸改性硅树脂的应用进行了展望。
本文通过柔性链节的引入改进了硅树脂和环氧树脂的柔韧性,所合成的树脂与普通硅树脂相比综合性能良好,集热稳定性、柔韧性、强度、一定的反应性于一体。合成的具备荧光性能的稀土金属离子配位聚硅氧烷为光性能有机硅材料的研究提供了理论依据。
学位年度:2009
作者:刘雷
学位授予单位:山东大学
关键词:线型聚硅氧烷;;柔性甲基苯基硅树脂;;有机硅改性环氧树脂;;光性能有机硅材料
摘要:
作为有机硅产品的重要组成部分,有机硅树脂兼有无机和有机材料的双重性能,是不同于一般有机树脂的特种高分子材料。
通常所用硅树脂虽然具有硬度高、耐磨、绝缘性能好等优点,但弹性欠佳,作为涂层材料在高、低温交变条件下有时会开裂,使其Cylinder neodymium magnet应用受到限制。为了解决这一问题,本论文开展了柔性硅树脂的研究,提出了合成柔性硅树脂的方法,并对其性能进行了改进。
本论文的研究主要分为四部分:
第一部分对硅树脂、线型聚硅氧烷、有机硅改性环氧树脂的合成方法、性能研究、应用进行了综述,为开展研究奠定了理论基础。
第二部分介绍柔性甲基苯基硅树脂的制备。本章从线型聚硅氧烷的合成入手,在偶联剂的作用下,将线型聚硅氧烷引入苯基氯硅烷水解物,制备了基体柔性有机硅树脂。探讨了聚硅氧烷的分子量、用量、偶联剂种类、固化剂http://www.chinamagnets.biz/种类等因素对树脂柔性的影响。并研究了溶剂用量、反应温度、原料配比、合成工艺等对树脂性能的影响。合成了柔性小于3mm并且耐温性达到300℃的有机硅树脂。
第三部分介绍有机硅改性环氧树脂的制备。本章首先以聚酰胺-650为偶联剂,两种线型聚硅氧烷为柔性链段,对环氧树脂TDE-85、双酚A型E-51进行了柔性改进,讨论了聚硅氧烷的分子量、用量等因素对环氧树脂性能的影响。以制备的柔性有机硅树脂为基体,通过引入适量的环氧树脂对其进行性能了改进,讨论了环氧树脂的用量、固化剂的种类、合成工艺对改性树脂柔韧性、剪切性能、耐温性能的影响。合成了柔性为3-4mm、耐温性在300-400℃的改性有机硅环氧树脂。
第四部分是一种新型光性能有机硅材料的研究。本章通过硅氢加成反应,制备了一种功能化的含酯基聚硅氧烷,通过与Eu和Tb两种稀Cylinder neodymium magnet土金属离子配位,制备出了具有红绿荧光性能的材料。详细表征了此种光性能材料的结构和光、热性能,对其在丙烯酸改性硅树脂的应用进行了展望。
本文通过柔性链节的引入改进了硅树脂和环氧树脂的柔韧性,所合成的树脂与普通硅树脂相比综合性能良好,集热稳定性、柔韧性、强度、一定的反应性于一体。合成的具备荧光性能的稀土金属离子配位聚硅氧烷为光性能有机硅材料的研究提供了理论依据。
学位年度:2009
碳纳米材料及其复合材料的合成与表征
题名:碳纳米材料及其复合材料的合成与表征
作者:李光达
学位授予单位:山东大学
关键词:纳米材料;;碳空心球;;碳纳米管;;复合材料
摘要:
本论文主要研究微尺度的碳材料的合成新方法,在对碳纳米管、碳空心球以及含碳复合材料的合成应用等方面的发展现状进行充分调研的基础上,采用过渡金属化合物还原法、催化分解法、水浴加热法等简单温和的制备方法和反应路线,成功的合成出不同直径的碳纳米管、碳空心球、碳实心球、碳橄榄球、碳纳米棒以Ring neodymium magnet及基于碳纳米管的稀土复合材料。通过实验结果的分析和相关的文献报道,分别对它们的生长机理和各种性质进行了探讨和研究。论文的主要内容归纳如下:
1.利用聚乙二醇(PEG)和NiC_2O_4、CoC_2O_4在450℃下反应,制备出了高产率的顶端分别包覆镍、钴金属颗粒的碳纳米管。利用二茂铁与NaN_3在350℃下反应,制备出了高产率的顶端包覆铁金属颗粒的碳纳米管。系统的研究了金属催化剂颗粒的大小与碳纳米管直径的关系,包覆金属颗粒的碳纳米管的磁性,碳纳米管http://www.chinamagnets.biz/的热稳定性,并对反应机理进行了探讨。
2.在成功合成碳纳米管的基础上,对所得的碳纳米管进行后处理,制备了碳纳米管表面负载稀土(Eu、La、Ce、Pr、Nb)氢氧化物的复合材料。实验过程在80℃水浴条件下进行,这种制备方法简单温和,可以用来合成其它许多含碳的复合材料。对碳纳米管与Eu氢氧化物的复合材料的研究表明,它可以表现出明显的光致发光。
3.丰富和发展了有机体系中合成碳纳Ring neodymium magnet米材料的制备技术。利用丙酮作为碳源,NaN_3作为催化剂,合成出了碳空心球。通过对反应物比例和催化剂的调整,制备出了碳实心球、碳橄榄球和碳纳米棒。并分别对其生长机理进行了讨论;并研究了碳空心球的热稳定性和比表面积。
学位年度:2009
作者:李光达
学位授予单位:山东大学
关键词:纳米材料;;碳空心球;;碳纳米管;;复合材料
摘要:
本论文主要研究微尺度的碳材料的合成新方法,在对碳纳米管、碳空心球以及含碳复合材料的合成应用等方面的发展现状进行充分调研的基础上,采用过渡金属化合物还原法、催化分解法、水浴加热法等简单温和的制备方法和反应路线,成功的合成出不同直径的碳纳米管、碳空心球、碳实心球、碳橄榄球、碳纳米棒以Ring neodymium magnet及基于碳纳米管的稀土复合材料。通过实验结果的分析和相关的文献报道,分别对它们的生长机理和各种性质进行了探讨和研究。论文的主要内容归纳如下:
1.利用聚乙二醇(PEG)和NiC_2O_4、CoC_2O_4在450℃下反应,制备出了高产率的顶端分别包覆镍、钴金属颗粒的碳纳米管。利用二茂铁与NaN_3在350℃下反应,制备出了高产率的顶端包覆铁金属颗粒的碳纳米管。系统的研究了金属催化剂颗粒的大小与碳纳米管直径的关系,包覆金属颗粒的碳纳米管的磁性,碳纳米管http://www.chinamagnets.biz/的热稳定性,并对反应机理进行了探讨。
2.在成功合成碳纳米管的基础上,对所得的碳纳米管进行后处理,制备了碳纳米管表面负载稀土(Eu、La、Ce、Pr、Nb)氢氧化物的复合材料。实验过程在80℃水浴条件下进行,这种制备方法简单温和,可以用来合成其它许多含碳的复合材料。对碳纳米管与Eu氢氧化物的复合材料的研究表明,它可以表现出明显的光致发光。
3.丰富和发展了有机体系中合成碳纳Ring neodymium magnet米材料的制备技术。利用丙酮作为碳源,NaN_3作为催化剂,合成出了碳空心球。通过对反应物比例和催化剂的调整,制备出了碳实心球、碳橄榄球和碳纳米棒。并分别对其生长机理进行了讨论;并研究了碳空心球的热稳定性和比表面积。
学位年度:2009
RuT340材质在6L缸盖上的应用研究
题名:RuT340材质在6L缸盖上的应用研究
作者:刘春雷
学位授予单位:上海交通大学
关键词:柴油机;;可靠性;;缸盖;;蠕铁;;蠕化处理;;铸造工艺
摘要:
近年来,蠕铁以其优异的性能逐渐推广应用于发动机缸体缸盖铸件,以适应发动机不断提高的可靠性要求。国内对于蠕铁的研Segment neodymium magnet究还停留在一些简单件的生产制作。玉柴率先在行业内进行了RuT340材质在重机6L缸盖上的研究应用。
本文通过两年多攻关过程中大量的试验对蠕化处理工艺、蠕铁铸造工艺进行详细深入的研究。
蠕化处理工艺方面主要通过正交试验得出了“稀土镁硅铁合金+稀土硅铁合金、硫含量≤0.025%、出铁温度1480℃”为合适的蠕化工艺参数组合Segment neodymium magnet;开发了高碳低硫工艺提升蠕铁的生产效率;通过球化处理包和搅拌的应用明显减少了蠕化不均匀状况;通过转包孕育相明显减少了孕育量,同时减少了白口;并论证了10<长厚比<50时,不代表铸件已经灰化,应以机械性能作为判定灰化依据的结论。
铸造工艺方面。通过大量的工艺试验创造并完善了压边冒口工艺,同时辅以型芯排气工艺,保证了7.85%的废品率远低于同类铸件的灰铁材质废品率。
本文还通过可靠性试验验http://www.chinamagnets.biz/证了RuT340材质的6L缸盖完全能适应重机高可靠性的要求。
学位年度:2009
作者:刘春雷
学位授予单位:上海交通大学
关键词:柴油机;;可靠性;;缸盖;;蠕铁;;蠕化处理;;铸造工艺
摘要:
近年来,蠕铁以其优异的性能逐渐推广应用于发动机缸体缸盖铸件,以适应发动机不断提高的可靠性要求。国内对于蠕铁的研Segment neodymium magnet究还停留在一些简单件的生产制作。玉柴率先在行业内进行了RuT340材质在重机6L缸盖上的研究应用。
本文通过两年多攻关过程中大量的试验对蠕化处理工艺、蠕铁铸造工艺进行详细深入的研究。
蠕化处理工艺方面主要通过正交试验得出了“稀土镁硅铁合金+稀土硅铁合金、硫含量≤0.025%、出铁温度1480℃”为合适的蠕化工艺参数组合Segment neodymium magnet;开发了高碳低硫工艺提升蠕铁的生产效率;通过球化处理包和搅拌的应用明显减少了蠕化不均匀状况;通过转包孕育相明显减少了孕育量,同时减少了白口;并论证了10<长厚比<50时,不代表铸件已经灰化,应以机械性能作为判定灰化依据的结论。
铸造工艺方面。通过大量的工艺试验创造并完善了压边冒口工艺,同时辅以型芯排气工艺,保证了7.85%的废品率远低于同类铸件的灰铁材质废品率。
本文还通过可靠性试验验http://www.chinamagnets.biz/证了RuT340材质的6L缸盖完全能适应重机高可靠性的要求。
学位年度:2009
T10表面激光熔覆Ni/WC-La_2O_3工艺与熔覆层性能研究
题名:T10表面激光熔覆Ni/WC-La_2O_3工艺与熔覆层性能研究
作者:欧阳志明
学位授予单位:华东交通大学
关键词:T10钢;;激光熔覆;;Ni基合金;;WC;;稀土氧化物La_2O_3;;Mo;;熔覆层性能
摘要:
激光熔覆是一种先进的材料表面改性技术,它是在基体上以不同的方式放置涂层材料,通过激光辐照使之和基体表面熔化,经过快速凝固后,形成低稀释率的、与基体呈冶金结合的表面涂层,从而改善材料的表面性能。这是一项发展非常迅速且具有广泛应用前景的材料加工新技术。
本文以T10钢为主要研究对象,重点研究了T10钢表面激光熔覆Ni基合金的工艺和熔覆层的显微组织、性能、裂纹的防止和搭Segment neodymium magnet接区的状况,并研究了在Ni基合金中加入WC硬质相、纳米稀土氧化物La2O3和Mo后的性能和组织结构的改变情况。
实验表明:激光熔覆后主要由三个区域组成,熔覆层、结合区、热影响区。在合适的工艺条件下可以得到结合性能良好的熔覆层。熔覆层的显微组织主要为粒状、棒状的胞晶结构,主要是受激光快速加热和快速冷却凝固影响的原因。在熔覆过程中,各处的加热速度和冷却速度存在很大的差异,使得熔覆层的硬度分布不是很均匀,在熔覆层的次表面具有最高硬度,达925.6HV0.1左右;耐磨性能也最好,相比熔覆前,提高了71%左右,这是晶粒细化和均匀化的原因。
Ni60+30%WC熔覆层的硬度与未加入WC相比改变不大,但是耐磨性却得到了很大的提高,裂纹的敏感性增加了很多,对比于未加入WC成份Segment neodymium magnet的熔覆,裂纹出现的几率提高了10%左右。
Ni60+2.5%Mo熔覆层由以细小的伪共晶结构为主的组织构成,熔覆层开裂敏感性降低,硬度稍有下降,但耐磨性并不降低。同时元素Mo使组织颗粒细化、均匀,减少了应力集中,同时减少了低熔点的硅化物和硼化物在晶界的偏聚,使熔覆层的韧性增加,塑性提高,裂纹敏感性降低。
Ni60+1.0%La2O3熔覆层主要由树枝晶组成,在激光熔覆层添加La2O3,起到细化枝晶的作用;在激光功率不变的情况下(2.5KW),随着扫描速率的增大(4mm/s-6mm/s),枝晶细化更加明显;同时激光熔覆层平均硬度比未加稀土的提高约150HV0.1,质量分数为1.0%纳米La2O3的多道熔覆层的耐磨性明显好于质量分数为1.5%纳米La2O3的熔覆层耐磨性。
利用SEM观察分析、显微硬度测定、耐磨性测试及正交试验分析等手段,研究了激光功率、扫描速度、离焦量对熔覆层的显微硬度、耐磨性和显微组织的影响。结果表明:在其他条件不变的情况下,随着激光功率的增加,熔Segment neodymium magnet覆层的显微硬度先增加后减小,材料表面的耐磨性能也有一个先增大后减小的过程。这是由熔覆中能量密度不同造成晶粒的大小不同所致。
以激光功率、扫描速度和离焦量三个工艺参数作为影响熔覆层性能的因素,并选择合适的水平进行正交试验,通过对实验结果的分析可获得熔覆层显微硬度和耐磨等性能优良的激光加工工艺参数。
学位年度:2009
作者:欧阳志明
学位授予单位:华东交通大学
关键词:T10钢;;激光熔覆;;Ni基合金;;WC;;稀土氧化物La_2O_3;;Mo;;熔覆层性能
摘要:
激光熔覆是一种先进的材料表面改性技术,它是在基体上以不同的方式放置涂层材料,通过激光辐照使之和基体表面熔化,经过快速凝固后,形成低稀释率的、与基体呈冶金结合的表面涂层,从而改善材料的表面性能。这是一项发展非常迅速且具有广泛应用前景的材料加工新技术。
本文以T10钢为主要研究对象,重点研究了T10钢表面激光熔覆Ni基合金的工艺和熔覆层的显微组织、性能、裂纹的防止和搭Segment neodymium magnet接区的状况,并研究了在Ni基合金中加入WC硬质相、纳米稀土氧化物La2O3和Mo后的性能和组织结构的改变情况。
实验表明:激光熔覆后主要由三个区域组成,熔覆层、结合区、热影响区。在合适的工艺条件下可以得到结合性能良好的熔覆层。熔覆层的显微组织主要为粒状、棒状的胞晶结构,主要是受激光快速加热和快速冷却凝固影响的原因。在熔覆过程中,各处的加热速度和冷却速度存在很大的差异,使得熔覆层的硬度分布不是很均匀,在熔覆层的次表面具有最高硬度,达925.6HV0.1左右;耐磨性能也最好,相比熔覆前,提高了71%左右,这是晶粒细化和均匀化的原因。
Ni60+30%WC熔覆层的硬度与未加入WC相比改变不大,但是耐磨性却得到了很大的提高,裂纹的敏感性增加了很多,对比于未加入WC成份Segment neodymium magnet的熔覆,裂纹出现的几率提高了10%左右。
Ni60+2.5%Mo熔覆层由以细小的伪共晶结构为主的组织构成,熔覆层开裂敏感性降低,硬度稍有下降,但耐磨性并不降低。同时元素Mo使组织颗粒细化、均匀,减少了应力集中,同时减少了低熔点的硅化物和硼化物在晶界的偏聚,使熔覆层的韧性增加,塑性提高,裂纹敏感性降低。
Ni60+1.0%La2O3熔覆层主要由树枝晶组成,在激光熔覆层添加La2O3,起到细化枝晶的作用;在激光功率不变的情况下(2.5KW),随着扫描速率的增大(4mm/s-6mm/s),枝晶细化更加明显;同时激光熔覆层平均硬度比未加稀土的提高约150HV0.1,质量分数为1.0%纳米La2O3的多道熔覆层的耐磨性明显好于质量分数为1.5%纳米La2O3的熔覆层耐磨性。
利用SEM观察分析、显微硬度测定、耐磨性测试及正交试验分析等手段,研究了激光功率、扫描速度、离焦量对熔覆层的显微硬度、耐磨性和显微组织的影响。结果表明:在其他条件不变的情况下,随着激光功率的增加,熔Segment neodymium magnet覆层的显微硬度先增加后减小,材料表面的耐磨性能也有一个先增大后减小的过程。这是由熔覆中能量密度不同造成晶粒的大小不同所致。
以激光功率、扫描速度和离焦量三个工艺参数作为影响熔覆层性能的因素,并选择合适的水平进行正交试验,通过对实验结果的分析可获得熔覆层显微硬度和耐磨等性能优良的激光加工工艺参数。
学位年度:2009
La_（2/3）Ba_（1/3）Cu_（0.15）Mn_（0.85）O_3薄膜和La_（0.7-x）Nd_xSr_（0.3）MnO_3的结构与磁性质的研究
题名:La_（2/3）Ba_（1/3）Cu_（0.15）Mn_（0.85）O_3薄膜和La_（0.7-x）Nd_xSr_（0.3）MnO_3的结构与磁性质的研究
作者:董苏雅拉图
学位授予单位:内蒙古大学
关键词:La_(2/3)Ba_(1/3)Cu_(0.15)Mn_(0.85)O_3薄膜;;La_(0.7-x)Nd_xSr_(0.3)MnO_3;;巨磁电阻效应;;晶体结构;;物理性质
摘要:
利用射频磁控溅射法结合后期退火处理,在Si(100)基片上制备了一系列的(La_(2/3)Ba_(1/3))(Cu_(0.15)Mn_(0.85)O_3)薄膜。通过X射线衍射(XRD)、扫描隧道显微镜(STM)、X射线光电子能谱(XPS)、标准四探针法等手段对薄膜进行了相结构、微结构特征、表面化学状态以及室温与液氮下的磁电阻随磁场变化特性rare earth magnets等的测试,结果表明薄膜在750℃就已形成正交钙钛矿结构,900℃时晶相变得更加完整,晶体内部各部分变得更加均匀。随着退火温度的升高,晶粒迅速长大,颗粒间的氧空位逐渐消失,晶格氧含量增加,促使磁电阻增强明显。
采用空气中固相反应烧http://www.chinamagnets.biz/结法制备了一系列钙钛矿结构的La_(0.7-x)Nd_xSr_(0.3)MnO_3(x=0,0.05,0.10,0.15,0.2)稀土锰氧化物多晶样品。X射线衍射(XRD)分析表明随着钕离子浓度的增加,晶胞体积逐渐减小。扫描电镜(SEM)观测的结果表明掺杂Nd离子含量越多,形成多晶样品的晶粒越小,未掺杂Nd的La_(0.7)Sr_(0.3)MnO_3在所有的样品中晶粒最大。红外吸收光谱测量发现样品在574～602cm~(-1)范围出现了吸收峰并且峰的rare earth magnets位置随掺杂Nd离子的含量增加而向低频方向偏移。样品的磁性质测量表明掺杂稀土离子的含量及磁矩对材料的磁电阻有明显影响。
学位年度:2009
作者:董苏雅拉图
学位授予单位:内蒙古大学
关键词:La_(2/3)Ba_(1/3)Cu_(0.15)Mn_(0.85)O_3薄膜;;La_(0.7-x)Nd_xSr_(0.3)MnO_3;;巨磁电阻效应;;晶体结构;;物理性质
摘要:
利用射频磁控溅射法结合后期退火处理,在Si(100)基片上制备了一系列的(La_(2/3)Ba_(1/3))(Cu_(0.15)Mn_(0.85)O_3)薄膜。通过X射线衍射(XRD)、扫描隧道显微镜(STM)、X射线光电子能谱(XPS)、标准四探针法等手段对薄膜进行了相结构、微结构特征、表面化学状态以及室温与液氮下的磁电阻随磁场变化特性rare earth magnets等的测试,结果表明薄膜在750℃就已形成正交钙钛矿结构,900℃时晶相变得更加完整,晶体内部各部分变得更加均匀。随着退火温度的升高,晶粒迅速长大,颗粒间的氧空位逐渐消失,晶格氧含量增加,促使磁电阻增强明显。
采用空气中固相反应烧http://www.chinamagnets.biz/结法制备了一系列钙钛矿结构的La_(0.7-x)Nd_xSr_(0.3)MnO_3(x=0,0.05,0.10,0.15,0.2)稀土锰氧化物多晶样品。X射线衍射(XRD)分析表明随着钕离子浓度的增加,晶胞体积逐渐减小。扫描电镜(SEM)观测的结果表明掺杂Nd离子含量越多,形成多晶样品的晶粒越小,未掺杂Nd的La_(0.7)Sr_(0.3)MnO_3在所有的样品中晶粒最大。红外吸收光谱测量发现样品在574～602cm~(-1)范围出现了吸收峰并且峰的rare earth magnets位置随掺杂Nd离子的含量增加而向低频方向偏移。样品的磁性质测量表明掺杂稀土离子的含量及磁矩对材料的磁电阻有明显影响。
学位年度:2009
近化学计量比及掺Nd~(3+)铌酸锂晶体的下降法生长研究
题名:近化学计量比及掺Nd~(3+)铌酸锂晶体的下降法生长研究
作者:王金浩
学位授予单位:浙江工业大学
关键词:铌酸锂;;晶体生长;;坩埚下降法;;Nd~(3+);;学计量比
摘要:
铌酸锂(LiNbO_3)晶体具有优良的压电、铁电、非线性、电光等性能、被广泛应用于声表面波、电光、声光、全息储存等器件。但由于铌酸锂晶体是一种典型的非化学计量比氧化物,普通方法生长的同成分铌酸锂晶体的Li/Nb=0.946,组分严重缺锂,对晶体的许多物理性能都产生了许多不利的影响,从而限制neodymium rare earth magnets了该晶体在一定条件下的使用。
我们通过选择合适的工艺条件如:控制固液界面处的温度梯度为40～60℃/cm、晶体生长速度为0.8-1.2mm/h,在密闭坩埚条件下以K_2O作为助熔剂,采用坩埚下降法生长获得了具有良好光学性能的近化学计量比铌酸锂晶体,对晶体的结构、组分、光学性能等进行测试分析。同时我们还对掺稀土的铌酸锂晶体的下降法生长工艺进行了研究。生长获得了Nd~(3+)等稀土离子掺杂的铌酸锂晶体, http://www.chinamagnets.biz/ 并对Nd~(3+)掺杂的铌酸锂晶体的吸收光谱、荧光光谱等进行了测试,用Judd—Ofelt理论计算了Nd~(3+)离子的谱线强度、自发辐射跃迁几率、辐射能级寿命、荧光分支比和受激发射截面等发光特性参数。拟合得neodymium rare earth magnets到了Nd~(3+)离子的强度参数Ω_λ:Ω_2=4.05×10~(-20)cm~2,Ω_4=2.71×10~(-20)cm~2,Ω_6=4.27×10~(-20)cm~2,对应于Nd~(3+)离子~3F_(3/2)→~4I_(11/2)跃迁的近红外1.06μm波段发光,计算得到其跃迁几率,荧光分支比和受激发射截面分别达到1189.3s~(-1)、0.52和1.02×10~(-20)cm~2。~3F_(3/2)能级的实验荧光寿命为240us,理论荧光寿命436us,量子效率55%。
学位年度:2009
作者:王金浩
学位授予单位:浙江工业大学
关键词:铌酸锂;;晶体生长;;坩埚下降法;;Nd~(3+);;学计量比
摘要:
铌酸锂(LiNbO_3)晶体具有优良的压电、铁电、非线性、电光等性能、被广泛应用于声表面波、电光、声光、全息储存等器件。但由于铌酸锂晶体是一种典型的非化学计量比氧化物,普通方法生长的同成分铌酸锂晶体的Li/Nb=0.946,组分严重缺锂,对晶体的许多物理性能都产生了许多不利的影响,从而限制neodymium rare earth magnets了该晶体在一定条件下的使用。
我们通过选择合适的工艺条件如:控制固液界面处的温度梯度为40～60℃/cm、晶体生长速度为0.8-1.2mm/h,在密闭坩埚条件下以K_2O作为助熔剂,采用坩埚下降法生长获得了具有良好光学性能的近化学计量比铌酸锂晶体,对晶体的结构、组分、光学性能等进行测试分析。同时我们还对掺稀土的铌酸锂晶体的下降法生长工艺进行了研究。生长获得了Nd~(3+)等稀土离子掺杂的铌酸锂晶体, http://www.chinamagnets.biz/ 并对Nd~(3+)掺杂的铌酸锂晶体的吸收光谱、荧光光谱等进行了测试,用Judd—Ofelt理论计算了Nd~(3+)离子的谱线强度、自发辐射跃迁几率、辐射能级寿命、荧光分支比和受激发射截面等发光特性参数。拟合得neodymium rare earth magnets到了Nd~(3+)离子的强度参数Ω_λ:Ω_2=4.05×10~(-20)cm~2,Ω_4=2.71×10~(-20)cm~2,Ω_6=4.27×10~(-20)cm~2,对应于Nd~(3+)离子~3F_(3/2)→~4I_(11/2)跃迁的近红外1.06μm波段发光,计算得到其跃迁几率,荧光分支比和受激发射截面分别达到1189.3s~(-1)、0.52和1.02×10~(-20)cm~2。~3F_(3/2)能级的实验荧光寿命为240us,理论荧光寿命436us,量子效率55%。
学位年度:2009
乳酸脱水反应催化剂的探索性研究
题名:乳酸脱水反应催化剂的探索性研究
作者:范能全
学位授予单位:浙江工业大学
关键词:乳酸;;脱水反应;;SiO_2;;锂皂石;;膨润土
摘要:
丙烯酸系一种重要的不饱和有机酸。传统的丙烯酸工业生产技术路线均是以石油资源作为原料,直接造成了丙烯酸的供应受到石油资源的供应和价格的影响。由生物发酵制取乳酸工艺的成熟发展,促使人们关注由乳酸脱水生成丙烯酸的研究。迄今为止,报道中关于乳酸脱水反应催化剂均存在着主产物选择性低、副产物strong magnets多等缺点。针对上述不足,本论文探索了三种乳酸脱水反应的催化剂,并利用X射线衍射(XRD)、傅立叶转换红外线光谱(FT-IR)、N_2等温吸附-脱附分析和扫描电境分析(SEM)等现代测试手段对催化剂进行了表征。以乳酸为反应物,对各催化剂的催化乳酸脱水性能进行了考察,得出它们物理结构性质与催化性能的关系。
本文从HZSM-5、自制SiO_2、市售SiO_2、活性炭、TiO_2、MgO、膨润土等材料中,优选自制SiO_2作为载体制备了负载Na_3PO_4型固体催化剂,在液固相条件下对乳酸进行催化活性测试。由研究可知催化剂的较佳制备条件为:负载量为1.0 mmol/g、浸渍温度为50℃、浸渍时间为3 h、焙烧温度为300℃、焙烧时间为3 h。其中FT-IR、XRD表征结果表明自制SiO_2具有与市售SiO_2相同的结构,而BET结果则显示两者在微观孔道结构和比表面积具有较大的差异。
以层状材料锂皂石为出发点,在表面活性剂十六烷基三甲基溴化铵(CTAB)和正十二烷胺(DDA)形成有单一的或混合表面活性剂的水热反应介质下原位合成锂皂石,通过FT-IR、XRD、SEM、TG-DTA、XPS、BET等分析技术手段对实验制得固体产物进行表征,以探讨生成锂皂石产物的可能性及相应的结构特征。再以稀土元素strong magnets铈对有机锂皂石进行改性后应用于乳酸脱水反应,考察其气固相条件下催化性能。未添加表面活性剂所制得催化剂样品的乳酸反应转化率为33.5%,而丙烯酸及乙醛的选择性分别为40.2%和1.8%。添加了表面活性剂样品对乳酸反应的转化率均有不同程度的提高,同时反应对乙醛的选择性会降低而丙烯酸的选择性会增加。对于反应副产物而言,基于锂皂石所制备的催化剂其副产物总选择性为45%左右较自制SiO_2所制备的固体催化剂有较大的改善。
基于锂皂石在自然界的稀缺性,选择同为层状材料的膨润土为出发点,利用不同质量浓度的磷酸对其进行酸化处理,再用稀土元素铈进行改性后应用于乳酸气固相脱水反应。原土直接应用于乳酸反应时,乳酸的转化率为15.3%而乙醛http://www.chinamagnets.biz/和丙烯酸的选择性分别为61.4%和2.5%;当用30%磷酸活化8 h的样品所制得的丙烯酸的产率较高,其转化率为80.8%,而丙烯酸和乙醛的选择性为51.8%和6.9%。同时实验还发现,基于膨润土体系反应的转化率较高,且副产物总选择性维持于32%左右。
学位年度:2009
作者:范能全
学位授予单位:浙江工业大学
关键词:乳酸;;脱水反应;;SiO_2;;锂皂石;;膨润土
摘要:
丙烯酸系一种重要的不饱和有机酸。传统的丙烯酸工业生产技术路线均是以石油资源作为原料,直接造成了丙烯酸的供应受到石油资源的供应和价格的影响。由生物发酵制取乳酸工艺的成熟发展,促使人们关注由乳酸脱水生成丙烯酸的研究。迄今为止,报道中关于乳酸脱水反应催化剂均存在着主产物选择性低、副产物strong magnets多等缺点。针对上述不足,本论文探索了三种乳酸脱水反应的催化剂,并利用X射线衍射(XRD)、傅立叶转换红外线光谱(FT-IR)、N_2等温吸附-脱附分析和扫描电境分析(SEM)等现代测试手段对催化剂进行了表征。以乳酸为反应物,对各催化剂的催化乳酸脱水性能进行了考察,得出它们物理结构性质与催化性能的关系。
本文从HZSM-5、自制SiO_2、市售SiO_2、活性炭、TiO_2、MgO、膨润土等材料中,优选自制SiO_2作为载体制备了负载Na_3PO_4型固体催化剂,在液固相条件下对乳酸进行催化活性测试。由研究可知催化剂的较佳制备条件为:负载量为1.0 mmol/g、浸渍温度为50℃、浸渍时间为3 h、焙烧温度为300℃、焙烧时间为3 h。其中FT-IR、XRD表征结果表明自制SiO_2具有与市售SiO_2相同的结构,而BET结果则显示两者在微观孔道结构和比表面积具有较大的差异。
以层状材料锂皂石为出发点,在表面活性剂十六烷基三甲基溴化铵(CTAB)和正十二烷胺(DDA)形成有单一的或混合表面活性剂的水热反应介质下原位合成锂皂石,通过FT-IR、XRD、SEM、TG-DTA、XPS、BET等分析技术手段对实验制得固体产物进行表征,以探讨生成锂皂石产物的可能性及相应的结构特征。再以稀土元素strong magnets铈对有机锂皂石进行改性后应用于乳酸脱水反应,考察其气固相条件下催化性能。未添加表面活性剂所制得催化剂样品的乳酸反应转化率为33.5%,而丙烯酸及乙醛的选择性分别为40.2%和1.8%。添加了表面活性剂样品对乳酸反应的转化率均有不同程度的提高,同时反应对乙醛的选择性会降低而丙烯酸的选择性会增加。对于反应副产物而言,基于锂皂石所制备的催化剂其副产物总选择性为45%左右较自制SiO_2所制备的固体催化剂有较大的改善。
基于锂皂石在自然界的稀缺性,选择同为层状材料的膨润土为出发点,利用不同质量浓度的磷酸对其进行酸化处理,再用稀土元素铈进行改性后应用于乳酸气固相脱水反应。原土直接应用于乳酸反应时,乳酸的转化率为15.3%而乙醛http://www.chinamagnets.biz/和丙烯酸的选择性分别为61.4%和2.5%;当用30%磷酸活化8 h的样品所制得的丙烯酸的产率较高,其转化率为80.8%,而丙烯酸和乙醛的选择性为51.8%和6.9%。同时实验还发现,基于膨润土体系反应的转化率较高,且副产物总选择性维持于32%左右。
学位年度:2009
2012年4月9日星期一
Research Progress in Rare Earth Luminescent Materials
Research Progress in Rare Earth Luminescent Materials
In this paper we will synthetically analyse and conclude the study background, actuality, progress and learning opinion of rare earth luminescent materials, discuss the synthesis and application study of rare earth luminescent materials generally, deeply and systematically, and introduce the new development, trend, level, principle and technology. Base on these, the luminescence principle and formation nature of the luminescent material were described, and the application and development prospect of were discussed and look forward to.This paper summarized several of rare earth luminescent materials synthetic methods used presently at home and abroad. The synthetic methods included high temperature solid method, sol-gel process, combustion synthesis, hydrothermal synthesis, microwave radiation method, micro-emulsion method and so on. By compared with the advantages and shortcomings of every method, the conclusion we obtained was high temperature solid method was best. The synthetic methods of rare earth luminescent materials were prospected. The existing commercial processes all adopt high temperature solid method, but the defects such as high reaction temperature, long time, high strong magnets energy loss are difficultly overcame.
The sol-gel process, chemical precipitation method, hydrothermal synthesis all possess some defects: reaction period is long, operation process is complex, realization of industrialization is not easy. Microwave radiation method had preferable foreground and applied worth, but the biggest obstacle of its development was there was a lack of the microwave furnace that was fit for the large industrialization production, combustion synthesis was a kind of promising method that rare earth luminescent materials were synthesized simply, quickly, efficiently at lower temperature by. Though the time that combustion synthesis was applied to the field of luminescent materials synthesis was short, it has put up the good application prospect. By experimental investigation, we thought combustion synthesis was the most promising technology that instead of high temperature solid method and make the industrialization come true. Micro-emulsion method and sol-gel process are relatively perfect methods for the preparation of rare earth luminescent materials with nanometer size, because the sizes of the materials were prepared by these methods could be nanometer level and the particles were uniform.
Rare earth with special morphology such as strong magnets nano-sphere, nano-rods and nano-tubes could be prepared by the control of the reactive conditions and the addition of certain adjuvant.Nearly, the development of rare earth luminescent materials’application was very rapid, rare earth luminescent materials include photoluminescence (excitation by UV-light or visible light), cathode luminescence (excitation by electron beam), X-ray luminescence (excitation by X-ray) and electroluminescence (excitation by electric field) materials. Compared with non-rare earth fluorescent materials, the performances of rare earth fluorescent materials such as luminous efficiency and light color are better. Rare earth luminescent materials have become the main materials in information display, light engineering and optical communication et al because the rare earth ion has the special structure of its 4f and 4f5d energy level and charge transition state. Rare earth is the important compose of a good many functional materials such as luminescence, magnetic and superconductor materials etc. The particular properties such as electronics and optics owing to the electron energy level transition among 4f electrons of rare earth ions were full of foreground combined with a good many characters of nano-materials were different with bulk materials, so rare-earths doped luminescence materials have attracted great attention since their extensive applications in the fields such as information display, optoelectronic devices and laser technology. strong magnets The characters of rare earth such as luminescence, magnetic, superconductor and so on were nearly relation with composes of the materials. So rare earth doped rare earth nanometer luminescent materials synchronously possessed the character of surface and quanta size effect synchronously were very promising functional material.
In this paper we will synthetically analyse and conclude the study background, actuality, progress and learning opinion of rare earth luminescent materials, discuss the synthesis and application study of rare earth luminescent materials generally, deeply and systematically, and introduce the new development, trend, level, principle and technology. Base on these, the luminescence principle and formation nature of the luminescent material were described, and the application and development prospect of were discussed and look forward to.This paper summarized several of rare earth luminescent materials synthetic methods used presently at home and abroad. The synthetic methods included high temperature solid method, sol-gel process, combustion synthesis, hydrothermal synthesis, microwave radiation method, micro-emulsion method and so on. By compared with the advantages and shortcomings of every method, the conclusion we obtained was high temperature solid method was best. The synthetic methods of rare earth luminescent materials were prospected. The existing commercial processes all adopt high temperature solid method, but the defects such as high reaction temperature, long time, high strong magnets energy loss are difficultly overcame.
The sol-gel process, chemical precipitation method, hydrothermal synthesis all possess some defects: reaction period is long, operation process is complex, realization of industrialization is not easy. Microwave radiation method had preferable foreground and applied worth, but the biggest obstacle of its development was there was a lack of the microwave furnace that was fit for the large industrialization production, combustion synthesis was a kind of promising method that rare earth luminescent materials were synthesized simply, quickly, efficiently at lower temperature by. Though the time that combustion synthesis was applied to the field of luminescent materials synthesis was short, it has put up the good application prospect. By experimental investigation, we thought combustion synthesis was the most promising technology that instead of high temperature solid method and make the industrialization come true. Micro-emulsion method and sol-gel process are relatively perfect methods for the preparation of rare earth luminescent materials with nanometer size, because the sizes of the materials were prepared by these methods could be nanometer level and the particles were uniform.
Rare earth with special morphology such as strong magnets nano-sphere, nano-rods and nano-tubes could be prepared by the control of the reactive conditions and the addition of certain adjuvant.Nearly, the development of rare earth luminescent materials’application was very rapid, rare earth luminescent materials include photoluminescence (excitation by UV-light or visible light), cathode luminescence (excitation by electron beam), X-ray luminescence (excitation by X-ray) and electroluminescence (excitation by electric field) materials. Compared with non-rare earth fluorescent materials, the performances of rare earth fluorescent materials such as luminous efficiency and light color are better. Rare earth luminescent materials have become the main materials in information display, light engineering and optical communication et al because the rare earth ion has the special structure of its 4f and 4f5d energy level and charge transition state. Rare earth is the important compose of a good many functional materials such as luminescence, magnetic and superconductor materials etc. The particular properties such as electronics and optics owing to the electron energy level transition among 4f electrons of rare earth ions were full of foreground combined with a good many characters of nano-materials were different with bulk materials, so rare-earths doped luminescence materials have attracted great attention since their extensive applications in the fields such as information display, optoelectronic devices and laser technology. strong magnets The characters of rare earth such as luminescence, magnetic, superconductor and so on were nearly relation with composes of the materials. So rare earth doped rare earth nanometer luminescent materials synchronously possessed the character of surface and quanta size effect synchronously were very promising functional material.
The Analysis of the Rare Earth Safety and Safety Strategy
The Analysis of the Rare Earth Safety and Safety Strategy
Resources safety is the base point of national security, and the nation should attachimportance to resources safety and the resources strategy highly.The policy ofpolitics,economy,diplomacy and national defense in our country, should consider thebase point of resources safety well.The rare earth is the important and strategic supplies which relates to economicsafety and national defense safety, and it is the essential original material in hightechnology and national defense realm such as aviation, semi-conductor, special kindsteel, heat-proof metal alloy and sophisticated weapon etc. The fact also shows thatthe level of the rare earth’s development and application in such country,rare earth magnets especially inthe high tech realm, is proportional to the developed degree of its industrialtechnology.Our country has the most abundant rare earth resources in the world, but theper-share of the resources is lower,and the phenomenon of the rudderless exploitationand waste is severe.
Because of the piece partitions and the confused market,there area lot of low-level redundant development in the rare earth industry,the supply of therare earth products always exceeds the demand,and the products’technology content islow.Meanwhile,the confused exportation leads to the low price of the export productsand the poor economic benefit,and the resources advantage can not develop well.Evenour country acquires the world champion of volume of production and sale quantitycurrently,that is on a certain degree exchanged with the sacrifice in great quantitiesprecious resources of short date of economic performance;in the meantime the lowlevel of the http://www.chinamagnets.biz/ production has already resulted in very serious pollution of theenvironment.In consideration of the consumption of resources and pollution of theenvironment from views of science development,the performance of the resourcesmining will give discount to even lose more than gain greatly.All of that is seciouslywaste to the non-reborn and strategic rare earth.
Therefore,conservatively mining therare earth resources,developing the rare earth industry,expanding the application ofthe rare earth,and changing the resources advantage as economic advantage,are theurgent need of developing economy and safeguarding national security in our country.This text aiming at the development and application condition of the rare earthresources all over the world,combining the strategy of sustainable development in ourcountry,considering the point of view of the resource safety,gives a define to thesafety of the rare resources.The rare earth safety is the supply safety,which mainlyembodys three aspects such as the reserves safety,produce safety and export safe ofthe rare earth.And through the investigation,conclusion and use for reference of theresources rare earth magnets safety strategy of some of developed countrys,combining the situation ofour country,the text put forward the resources safety strategy to protect the rare earthresources,which mainly includes eight suggestions:found the independent China RareEarth Guild,strengthen to reconnoitre the rare earth resources,reorganize and regulatethe mining order,improve the products’ technology content,enhance the export controlto the rara earth,base ourself upon the domestic consumption market,make use of theforeign rare earth resources, establish the strategy reserves of the rare earth resourcesin our country.
Resources safety is the base point of national security, and the nation should attachimportance to resources safety and the resources strategy highly.The policy ofpolitics,economy,diplomacy and national defense in our country, should consider thebase point of resources safety well.The rare earth is the important and strategic supplies which relates to economicsafety and national defense safety, and it is the essential original material in hightechnology and national defense realm such as aviation, semi-conductor, special kindsteel, heat-proof metal alloy and sophisticated weapon etc. The fact also shows thatthe level of the rare earth’s development and application in such country,rare earth magnets especially inthe high tech realm, is proportional to the developed degree of its industrialtechnology.Our country has the most abundant rare earth resources in the world, but theper-share of the resources is lower,and the phenomenon of the rudderless exploitationand waste is severe.
Because of the piece partitions and the confused market,there area lot of low-level redundant development in the rare earth industry,the supply of therare earth products always exceeds the demand,and the products’technology content islow.Meanwhile,the confused exportation leads to the low price of the export productsand the poor economic benefit,and the resources advantage can not develop well.Evenour country acquires the world champion of volume of production and sale quantitycurrently,that is on a certain degree exchanged with the sacrifice in great quantitiesprecious resources of short date of economic performance;in the meantime the lowlevel of the http://www.chinamagnets.biz/ production has already resulted in very serious pollution of theenvironment.In consideration of the consumption of resources and pollution of theenvironment from views of science development,the performance of the resourcesmining will give discount to even lose more than gain greatly.All of that is seciouslywaste to the non-reborn and strategic rare earth.
Therefore,conservatively mining therare earth resources,developing the rare earth industry,expanding the application ofthe rare earth,and changing the resources advantage as economic advantage,are theurgent need of developing economy and safeguarding national security in our country.This text aiming at the development and application condition of the rare earthresources all over the world,combining the strategy of sustainable development in ourcountry,considering the point of view of the resource safety,gives a define to thesafety of the rare resources.The rare earth safety is the supply safety,which mainlyembodys three aspects such as the reserves safety,produce safety and export safe ofthe rare earth.And through the investigation,conclusion and use for reference of theresources rare earth magnets safety strategy of some of developed countrys,combining the situation ofour country,the text put forward the resources safety strategy to protect the rare earthresources,which mainly includes eight suggestions:found the independent China RareEarth Guild,strengthen to reconnoitre the rare earth resources,reorganize and regulatethe mining order,improve the products’ technology content,enhance the export controlto the rara earth,base ourself upon the domestic consumption market,make use of theforeign rare earth resources, establish the strategy reserves of the rare earth resourcesin our country.
2012年4月4日星期三
滇西北衙地区新生代富碱斑岩的岩石学及地球化学特征及与金成矿的关系
题名:滇西北衙地区新生代富碱斑岩的岩石学及地球化学特征及与金成矿的关系
作者:黄行凯
学位授予单位:中国地质大学（北京）
关键词:富碱斑岩;;起源和成因;;滇西北衙
摘要:
滇西北衙及其周围地区地质构造复杂,成矿潜力很大,是一个重要的金多金属资源富集区。本文在收集整理前人研究资料的基础上,将深入的野外观察与深入的室内综合研究工作相结合,重点通过对滇西北衙新生代富碱斑岩的岩石学、年代学、地球化学特征的系统研究,探讨富碱斑岩的源区特征和成因,并通过对不同类型矿床的时空分布、矿床地质特征和构造特征的观察和研究,揭示该区富碱斑岩与金成矿作用的关系。研究表明:北衙矿区外围地区炭窑石英正长斑岩的SHRIMP年龄TY-1为31.5±1.1Ma,TY-3为31.34±0.73 Ma,与前人研究测试的年龄基本相符,将该区的富碱斑岩的侵位时代限定为新生代;北Alnico magnets衙地区富碱斑岩常量、微量元素地球化学等方面的特征表明,富碱斑岩总体属于钾玄岩系列岩石,岩石∑REE较低在40.04×10-6~298.30×10-6之间,具轻稀土富集型,没有或具有轻微的负铕异常;较高的Sr值和低的Y和Yb,以及富集大离子亲石元素(LILE,如Rb、Ba、K等)和亏损高场强元素(HFSE,如Nb、Ta等)的地球化学特征,与埃达克岩具有相似性;岩石Sr、Nd、Pb同位素地球化学特征揭示源区具有EMII型富集地幔的特征;富碱斑岩成因于滇西金沙江-红河http://www.999magnet.com/断裂带受印度-亚洲板块晚碰撞造山作用影响,发生大规模走滑拉分作用,和/或印缅地块和扬子地块斜向碰撞和相向俯冲引发的深部软流圈物质上涌的热侵蚀,致使加厚地壳部分熔融,在此过程中源区物质曾遭受古老俯冲板片的广泛交代;结合该区不同类型矿床与斑岩的时空分布特征、构造特征以及矿床流体包裹体和本区矿石和富碱斑岩的S、Pb同位素Alnico magnets组成特征的研究,揭示该区富碱斑岩岩浆在成矿过程中,不仅为含矿流体的上升提供了动力和热能,而且还是成矿物质和成矿流体的主要来源,北衙金多金属矿整个成矿事件统一受控于富碱斑岩-热液成矿系统。
学位年度:2009
作者:黄行凯
学位授予单位:中国地质大学（北京）
关键词:富碱斑岩;;起源和成因;;滇西北衙
摘要:
滇西北衙及其周围地区地质构造复杂,成矿潜力很大,是一个重要的金多金属资源富集区。本文在收集整理前人研究资料的基础上,将深入的野外观察与深入的室内综合研究工作相结合,重点通过对滇西北衙新生代富碱斑岩的岩石学、年代学、地球化学特征的系统研究,探讨富碱斑岩的源区特征和成因,并通过对不同类型矿床的时空分布、矿床地质特征和构造特征的观察和研究,揭示该区富碱斑岩与金成矿作用的关系。研究表明:北衙矿区外围地区炭窑石英正长斑岩的SHRIMP年龄TY-1为31.5±1.1Ma,TY-3为31.34±0.73 Ma,与前人研究测试的年龄基本相符,将该区的富碱斑岩的侵位时代限定为新生代;北Alnico magnets衙地区富碱斑岩常量、微量元素地球化学等方面的特征表明,富碱斑岩总体属于钾玄岩系列岩石,岩石∑REE较低在40.04×10-6~298.30×10-6之间,具轻稀土富集型,没有或具有轻微的负铕异常;较高的Sr值和低的Y和Yb,以及富集大离子亲石元素(LILE,如Rb、Ba、K等)和亏损高场强元素(HFSE,如Nb、Ta等)的地球化学特征,与埃达克岩具有相似性;岩石Sr、Nd、Pb同位素地球化学特征揭示源区具有EMII型富集地幔的特征;富碱斑岩成因于滇西金沙江-红河http://www.999magnet.com/断裂带受印度-亚洲板块晚碰撞造山作用影响,发生大规模走滑拉分作用,和/或印缅地块和扬子地块斜向碰撞和相向俯冲引发的深部软流圈物质上涌的热侵蚀,致使加厚地壳部分熔融,在此过程中源区物质曾遭受古老俯冲板片的广泛交代;结合该区不同类型矿床与斑岩的时空分布特征、构造特征以及矿床流体包裹体和本区矿石和富碱斑岩的S、Pb同位素Alnico magnets组成特征的研究,揭示该区富碱斑岩岩浆在成矿过程中,不仅为含矿流体的上升提供了动力和热能,而且还是成矿物质和成矿流体的主要来源,北衙金多金属矿整个成矿事件统一受控于富碱斑岩-热液成矿系统。
学位年度:2009
山西省五台县东腰庄金矿岩石地球化学特征与矿物学填图
题名:山西省五台县东腰庄金矿岩石地球化学特征与矿物学填图
作者:卢静
学位授予单位:中国地质大学（北京）
关键词:绿岩带型金矿;;五台山绿岩带;;岩石地球化学;;矿物学填图;;东腰庄金矿
摘要:
东腰庄金矿位于山西省五台县境内,是五台山绿岩带金矿中发现的一种新型式的金矿床类型。成矿年龄为2451Ma±。矿床的赋矿地层主要为五台群鸿门岩组,赋矿围岩主要为绢云钠长(石英)片岩和钠长绿泥片岩。金矿床具明显的层控性特征,在赋矿围岩上主要受绢云钠长(石英)片岩的产出控制,构造上严格受台怀—李家Magnetic lifter庄同斜倒转复式向斜与李家庄—大草坪韧性剪切带控制,故其又被认为是一个较典型的剪切带型金矿床。通过矿物学、岩石学和矿床学的研究,确定此类金矿的找矿标志,对于五台山绿岩带金矿勘查与研究具有重要意义。
本文主要研究了该矿区赋矿围岩的岩石地球化学和矿石中石英的流体包裹体特征,并对蚀变岩进行了短波红外光谱和磁化率的系统矿物学填图,从而对蚀变矿物及蚀变岩的分布规律以及其与金矿化之间的关系进行了探讨,取得的主要认识如下:
(1)微量元素分析显示,矿区中的各类变质岩均表现出轻稀土富集、重稀土亏损和铕的弱正异常的特征。原岩恢复表明,绢英片岩和绿泥片岩均为火山成因,属钙碱性-高钾钙碱性系列,绢英片岩原岩应属流纹英安岩-英安岩,绿泥片岩原岩应属安山岩-玄武岩。
(2)矿石的石英流体包裹体可分为四种类型:Ⅰ型气液两相包裹体、Ⅱ型纯气体包裹体、Ⅲ型CO2包裹体、Ⅳ型硅酸盐熔融包裹体,并以Ⅰ型气液两相包裹体为主要的包裹体类型。包裹体大小主要在2~12μm之间。均一温度直方图呈近Magnetic lifter正态多峰分布,主要有四个峰值区间,第一峰值区间为360~400℃,第二个为280~340℃,第三个为240~260℃,第四个为100~220℃。其中第四峰值区间为本矿床的主成矿温度。成矿流体的液相成分主要是Mg~(2+)、Na~+、SO_4~(2-)、Cl~-以及少量的K~+、Ca~(2+)、F~+,气相成分以水为主,并含有H_2、N_2和CO,属低盐度、中等密度流体。
(3)利用PIMA对本矿区蚀变矿物进行识别,表明白云母(绢云母)和绿泥石是矿区内分布最广泛的蚀变矿物。矿区内的蚀变矿物的空间分布及含量具有较强的规律性,明显受岩性控制。蚀变分带较明显,与金矿化关系密切的蚀变矿物为白云母(特别是结晶度高、层间水强度低的白云母)、伊利石、电气石。
(4)蚀变岩的磁化率研究表明,不同矿化蚀变类型岩石的磁化率之间的关系为:磁铁矿化>绿泥石化>绢英岩化>硅化电气石化>硅化碳酸盐化。在金矿化好的地段,磁化率普遍较低,且磁化率与金品位的变化趋势呈负相关的关系。综合分析上述研究成果,笔者提出本区同类型金矿的主要识别标志是:a.韧性剪切带附近;b.变辉绿岩带间的绢Magnetic lifter云钠长片岩带;c.电气石化+黄铁矿化+硅化发育带;d.黄铜矿和绢云母的出现;e.磁化率低值异常区,特别是极高值异常之间的低值异常区。
学位年度:2009
作者:卢静
学位授予单位:中国地质大学（北京）
关键词:绿岩带型金矿;;五台山绿岩带;;岩石地球化学;;矿物学填图;;东腰庄金矿
摘要:
东腰庄金矿位于山西省五台县境内,是五台山绿岩带金矿中发现的一种新型式的金矿床类型。成矿年龄为2451Ma±。矿床的赋矿地层主要为五台群鸿门岩组,赋矿围岩主要为绢云钠长(石英)片岩和钠长绿泥片岩。金矿床具明显的层控性特征,在赋矿围岩上主要受绢云钠长(石英)片岩的产出控制,构造上严格受台怀—李家Magnetic lifter庄同斜倒转复式向斜与李家庄—大草坪韧性剪切带控制,故其又被认为是一个较典型的剪切带型金矿床。通过矿物学、岩石学和矿床学的研究,确定此类金矿的找矿标志,对于五台山绿岩带金矿勘查与研究具有重要意义。
本文主要研究了该矿区赋矿围岩的岩石地球化学和矿石中石英的流体包裹体特征,并对蚀变岩进行了短波红外光谱和磁化率的系统矿物学填图,从而对蚀变矿物及蚀变岩的分布规律以及其与金矿化之间的关系进行了探讨,取得的主要认识如下:
(1)微量元素分析显示,矿区中的各类变质岩均表现出轻稀土富集、重稀土亏损和铕的弱正异常的特征。原岩恢复表明,绢英片岩和绿泥片岩均为火山成因,属钙碱性-高钾钙碱性系列,绢英片岩原岩应属流纹英安岩-英安岩,绿泥片岩原岩应属安山岩-玄武岩。
(2)矿石的石英流体包裹体可分为四种类型:Ⅰ型气液两相包裹体、Ⅱ型纯气体包裹体、Ⅲ型CO2包裹体、Ⅳ型硅酸盐熔融包裹体,并以Ⅰ型气液两相包裹体为主要的包裹体类型。包裹体大小主要在2~12μm之间。均一温度直方图呈近Magnetic lifter正态多峰分布,主要有四个峰值区间,第一峰值区间为360~400℃,第二个为280~340℃,第三个为240~260℃,第四个为100~220℃。其中第四峰值区间为本矿床的主成矿温度。成矿流体的液相成分主要是Mg~(2+)、Na~+、SO_4~(2-)、Cl~-以及少量的K~+、Ca~(2+)、F~+,气相成分以水为主,并含有H_2、N_2和CO,属低盐度、中等密度流体。
(3)利用PIMA对本矿区蚀变矿物进行识别,表明白云母(绢云母)和绿泥石是矿区内分布最广泛的蚀变矿物。矿区内的蚀变矿物的空间分布及含量具有较强的规律性,明显受岩性控制。蚀变分带较明显,与金矿化关系密切的蚀变矿物为白云母(特别是结晶度高、层间水强度低的白云母)、伊利石、电气石。
(4)蚀变岩的磁化率研究表明,不同矿化蚀变类型岩石的磁化率之间的关系为:磁铁矿化>绿泥石化>绢英岩化>硅化电气石化>硅化碳酸盐化。在金矿化好的地段,磁化率普遍较低,且磁化率与金品位的变化趋势呈负相关的关系。综合分析上述研究成果,笔者提出本区同类型金矿的主要识别标志是:a.韧性剪切带附近;b.变辉绿岩带间的绢Magnetic lifter云钠长片岩带;c.电气石化+黄铁矿化+硅化发育带;d.黄铜矿和绢云母的出现;e.磁化率低值异常区,特别是极高值异常之间的低值异常区。
学位年度:2009
辽宁后仙峪硼矿床矿物学和地球化学特征
题名:辽宁后仙峪硼矿床矿物学和地球化学特征
作者:王艳丽
学位授予单位:中国地质大学（北京）
关键词:后仙峪硼矿床;;含矿岩系;;地球化学;;矿物学;;电气石
摘要:
辽东早元古代的硼矿床代表了全球最大规模的前寒武纪成硼蒸发盆地。蒸发岩系中硼酸盐及其他矿产类型(铁、稀土、铀)的集中出现及其共生关系吸引了众多地质学家的重视。本论文依托国家自然科学基金项目(项目号:40373023),项Neodymium Magnets目名称:辽宁东部-吉林南部地区早元古代硼大规模富集过程的矿物学和地球化学记录。本文以前寒武纪地体辽宁后仙峪硼矿床(西石洞沟矿段)的含硼岩系为研究对象,通过野外地质观察和部分测试,对含矿岩系中的变粒岩、浅粒岩的矿物学、岩石学、地球化学及短波红外光谱特征进行研究,初步得出以下结论:
(1)含矿层中B_2O_3的富集程度与含矿层的厚度变化呈正相关关系;而矿体中B2O3富集程度与矿体厚度变化相关性不明显。(2)整个区域内变、浅粒岩中的钾钠呈现负增长(钾、钠分带),靠近矿体富钾,远离矿体富钠。该分带http://www.999magnet.com/现象代表了岩石原始的沉积环境是蒸发环境。(3)靠近硼酸盐矿体的电气石比远离矿体的电气石有更高的镁铁比值。电气石环带的镁铁比不同导致环带的颜色差异,褐色电气石富铁,蓝绿色电气石富镁。(4)矿区内电气石基本都存在于矿体的上盘,是指示性矿物。电气石是在热液过程中通过淋滤下伏含硼蒸发岩中的硼,形成含硼热液,在与上覆沉积物交代过程中形成。(5)矿物的短波红外光谱研究表明,区内Fe-Mg矿物普遍出现,并且含量较多。含矿层出现的绿泥石主要为镁绿泥石,与电气石的Mg/Fe变化情况一致。这一现象说明,矿体形成的环境较富含镁,与镁是硼酸岩最好的Neodymium Magnets沉淀剂这一结论相符。(6)该地区富钾钠岩石的原岩不是一般意义上的火山熔岩或者火山碎屑岩,而是后经过蒸发盆地蚀变改造的碎屑岩。硼酸盐的初始沉积环境是蒸发盆地。
学位年度:2009
作者:王艳丽
学位授予单位:中国地质大学（北京）
关键词:后仙峪硼矿床;;含矿岩系;;地球化学;;矿物学;;电气石
摘要:
辽东早元古代的硼矿床代表了全球最大规模的前寒武纪成硼蒸发盆地。蒸发岩系中硼酸盐及其他矿产类型(铁、稀土、铀)的集中出现及其共生关系吸引了众多地质学家的重视。本论文依托国家自然科学基金项目(项目号:40373023),项Neodymium Magnets目名称:辽宁东部-吉林南部地区早元古代硼大规模富集过程的矿物学和地球化学记录。本文以前寒武纪地体辽宁后仙峪硼矿床(西石洞沟矿段)的含硼岩系为研究对象,通过野外地质观察和部分测试,对含矿岩系中的变粒岩、浅粒岩的矿物学、岩石学、地球化学及短波红外光谱特征进行研究,初步得出以下结论:
(1)含矿层中B_2O_3的富集程度与含矿层的厚度变化呈正相关关系;而矿体中B2O3富集程度与矿体厚度变化相关性不明显。(2)整个区域内变、浅粒岩中的钾钠呈现负增长(钾、钠分带),靠近矿体富钾,远离矿体富钠。该分带http://www.999magnet.com/现象代表了岩石原始的沉积环境是蒸发环境。(3)靠近硼酸盐矿体的电气石比远离矿体的电气石有更高的镁铁比值。电气石环带的镁铁比不同导致环带的颜色差异,褐色电气石富铁,蓝绿色电气石富镁。(4)矿区内电气石基本都存在于矿体的上盘,是指示性矿物。电气石是在热液过程中通过淋滤下伏含硼蒸发岩中的硼,形成含硼热液,在与上覆沉积物交代过程中形成。(5)矿物的短波红外光谱研究表明,区内Fe-Mg矿物普遍出现,并且含量较多。含矿层出现的绿泥石主要为镁绿泥石,与电气石的Mg/Fe变化情况一致。这一现象说明,矿体形成的环境较富含镁,与镁是硼酸岩最好的Neodymium Magnets沉淀剂这一结论相符。(6)该地区富钾钠岩石的原岩不是一般意义上的火山熔岩或者火山碎屑岩,而是后经过蒸发盆地蚀变改造的碎屑岩。硼酸盐的初始沉积环境是蒸发盆地。
学位年度:2009
二氧化硅稀土发光材料的制备及性能研究
题名:二氧化硅稀土发光材料的制备及性能研究
作者:江东
学位授予单位:西北大学
关键词:溶胶-凝胶法;;水热法;;稀土掺杂;;光致发光(PL);;微观结构
摘要:
分别采用溶胶-凝胶法(sol-gel)和水热反应制备了掺杂Eu的SiO_2干凝胶、发光薄膜，通过荧光(PL)光谱、透射电镜(TEM)、扫描电镜(SEM)、原子力显微镜(AFM)、红外吸收谱(IR)等现代分析手段对样品进行了表征，研究了前magnet lifter驱液配比、掺杂浓度、退火温度等对材料微观结构、表面形貌及发光性能的影响，并对其发光机理进行了分析。
经溶胶-凝胶法制备的干凝胶样品，掺杂均匀，颗粒尺寸在50-80nm，硼(B)离子进入SiO_2网格，形成了Si-O-B键，改变了基质的网络结构。采用258nm激发时，随着退火温度的升高，红光发射强度先增强后减弱，经800℃退火处理样品的红光发射最强，出现了576nm(~5D_0→7F_0)，620nm(~5D_0→~7F_2)，658nm(~5D_0→~7F_3)3条谱线，其中主峰位于620nm红光发射，对应于Eu~(3+)离子的~5D_0→~7F_2超灵敏跃迁。随着退火温度的升高，蓝光发射强度先增强后减弱，经850℃退火的样品400-500nm蓝光发射最强，归属于Eu~(2+)的5d→4f的跃迁发射，证明在铝离子(Al~(3+))存在的情形下，在高温退火过程中，使得Eu~(3+)还原成Eu~(2+)，从而得到了较强的蓝光发射。经1450℃真空退火处理的样品，随着掺杂浓度的增加蓝光发射先增强后减弱，并且谱线http://www.999magnet.com/产生了红移，当Eu掺杂量x=0．4％时，其蓝光发射强度达到最强。
经溶胶-凝胶法制备的薄膜样品表面均匀，表面起伏较小，退火处理有助于改善薄膜的表面均匀度。在紫外光激发下，出现了比较少见的双峰红光发射,~5D_0→~7F_2跃迁发射最强，说明Eu~(3+)离子处在对称性较低的配位环境中。退火处理温度对薄膜样品的发射光谱影响很大，经900℃退火处理样品发射强度达到最强。
采用水热法制备的薄膜表面粗糙度较大，以262nm激发样品，在615nm和674nm处出现了双峰发射，经850℃退火处理的样品光发射magnet lifter最强，掺Al离子的发光薄膜，发射强度明显下降。以258nm激发干凝胶样品，出现615nm的红光发射和578nm的橙黄色发射，随着退火温度的升高发光强度逐渐增强，经750℃退火处理干凝胶样品红光发射最强。
学位年度:2009
作者:江东
学位授予单位:西北大学
关键词:溶胶-凝胶法;;水热法;;稀土掺杂;;光致发光(PL);;微观结构
摘要:
分别采用溶胶-凝胶法(sol-gel)和水热反应制备了掺杂Eu的SiO_2干凝胶、发光薄膜，通过荧光(PL)光谱、透射电镜(TEM)、扫描电镜(SEM)、原子力显微镜(AFM)、红外吸收谱(IR)等现代分析手段对样品进行了表征，研究了前magnet lifter驱液配比、掺杂浓度、退火温度等对材料微观结构、表面形貌及发光性能的影响，并对其发光机理进行了分析。
经溶胶-凝胶法制备的干凝胶样品，掺杂均匀，颗粒尺寸在50-80nm，硼(B)离子进入SiO_2网格，形成了Si-O-B键，改变了基质的网络结构。采用258nm激发时，随着退火温度的升高，红光发射强度先增强后减弱，经800℃退火处理样品的红光发射最强，出现了576nm(~5D_0→7F_0)，620nm(~5D_0→~7F_2)，658nm(~5D_0→~7F_3)3条谱线，其中主峰位于620nm红光发射，对应于Eu~(3+)离子的~5D_0→~7F_2超灵敏跃迁。随着退火温度的升高，蓝光发射强度先增强后减弱，经850℃退火的样品400-500nm蓝光发射最强，归属于Eu~(2+)的5d→4f的跃迁发射，证明在铝离子(Al~(3+))存在的情形下，在高温退火过程中，使得Eu~(3+)还原成Eu~(2+)，从而得到了较强的蓝光发射。经1450℃真空退火处理的样品，随着掺杂浓度的增加蓝光发射先增强后减弱，并且谱线http://www.999magnet.com/产生了红移，当Eu掺杂量x=0．4％时，其蓝光发射强度达到最强。
经溶胶-凝胶法制备的薄膜样品表面均匀，表面起伏较小，退火处理有助于改善薄膜的表面均匀度。在紫外光激发下，出现了比较少见的双峰红光发射,~5D_0→~7F_2跃迁发射最强，说明Eu~(3+)离子处在对称性较低的配位环境中。退火处理温度对薄膜样品的发射光谱影响很大，经900℃退火处理样品发射强度达到最强。
采用水热法制备的薄膜表面粗糙度较大，以262nm激发样品，在615nm和674nm处出现了双峰发射，经850℃退火处理的样品光发射magnet lifter最强，掺Al离子的发光薄膜，发射强度明显下降。以258nm激发干凝胶样品，出现615nm的红光发射和578nm的橙黄色发射，随着退火温度的升高发光强度逐渐增强，经750℃退火处理干凝胶样品红光发射最强。
学位年度:2009
2012年4月3日星期二
Studies on the Electronic Structures and Magnetism Driven by Defects in Sc Doped ZnO Thin Film
Studies on the Electronic Structures and Magnetism Driven by Defects in Sc Doped ZnO Thin Film
Recently, it has been one of the most important issues torealize diluted magnetic semiconductor with its criticaltemperature equal or above room temperature. Besides, thin filmswithout partially filled d or f shells of transition metal orrare earth element but exhibit Tc above room temperature havearoused public interest. We theoretically studied the possibleferromagnetism origin in ZnO thin film with 5% Sc doping by usingplane-wave pseudo-potential method based on the state-of-artDFT. Generally, In DMS materials the delocalized conduction bandelectrons and valence Neodymium Magnets band holes interact with the localizedmagnetic moments associated with the d or f electrons in magneticatoms. However, those materials such as ZnO thin film with 5%Scdoping, HfO2 thin film, CaB6,SrB6 and radiated graphite allcontain no partially filled d or f shells of transition metalor rare earth element, but exhibit Tc above room temperature.Considering that all of them are film materials ,and ,it is wellknown that the film materials have larger ratio of area andbulk ,therefore the intrinsic defects during the growth of thinfilm would have great influence on there physical properties.As for CaB6 and SrB6, it has been proved experimentally that themagnetic moment per formulas in thin film is two or four timelarger in orders of magnitude than that in the single crystalor polycrystalline materials. And the theoretical calculationsrelated to it proved that the B6 vacancy in CaB6 carries a magneticmoment of 2.4μB. As for HfO2, it has been reported that the thinfilm exhibits ferromagnetism with Tc above 500K, but no in thebulk materials. And calculation on HfO2 proved that the Hfvacancy in HfO2 exhibits a magnetic moment Neodymium Magnets of 3.5μB, and themagnetic moments are ferromagnetic coupled.
As for graphite, ithas been proved experimentally that the nonmagnetic graphitewould exhibit ferromagnetism after it is radiated with http://www.999magnet.com/ highenergy particles. And calculation proved that vacancy or thecomplex of vacancy and hydrogen carries magnetic moment. As forZnO, it is well known that ZnO is non-ferromagnetic. Andtheoretical calculation showed that ZnO with one Zn atomsubstituted with Sc exhibited no ferromagnetism. Defects insimple oxides that trap two electrons or two holes are known tohave triplet ground state or low-lying triplet excited state.The role of the dopant is to stabilize the triplet ground state.It will produce Zn vacancy in (Zn0.95Sc0.05)O when Zn+2is substitutedwith Sc+3,therefore Zn vacancy will play an important role in ZnOthin film with Sc doping .we theoretically studied the effectof Sc on the VZn so as to search for the possible ferromagneticorigin.Firstly, I studied the influence of the intrinsic defectssuch as VO= and VZn on the magnetism of ZnO thin film. And I got1.8μB/VZn in Zn15O16, but not in Zn16O15. Secondly, we studied theeffect of Sc on the magnetism.
We performed spin-polarizedelectronic calculation on the supercell Zn14Sc1O16, whichcontains Sc and VZn. We got 1.0μB/VZn. In order to simulateactual doping :two Sc atoms will introduce one VZn, We got netmagnetic moment of 0.4μB/VZn, which agrees well with theexperimental result 0.2-0.3μB/VZn. Thirdly, we studied thechange of magnetic moment with the Neodymium Magnets distance of Sc and VZn. Wegot that: it results no change on the magnetism moment, butthe redistribute of magnetic moment on the neighboring atoms.We also calculated the effect of Sc on the formation energyof VZn. We got that: With the introduction of Sc, the formationenergy of VZn reduced apparently, which means Sc favors theformation of VZn .We also calculated and compared the totalenergy of Zn14Sc1O16 with the magnetism moment coupledferromagnetically and antiferromagnetically. We got that theferromagnetic configuration has smaller energy. Then we drawa conclusion that: VZn is the origin of ZnO thin film with 5%Sc doping.
Recently, it has been one of the most important issues torealize diluted magnetic semiconductor with its criticaltemperature equal or above room temperature. Besides, thin filmswithout partially filled d or f shells of transition metal orrare earth element but exhibit Tc above room temperature havearoused public interest. We theoretically studied the possibleferromagnetism origin in ZnO thin film with 5% Sc doping by usingplane-wave pseudo-potential method based on the state-of-artDFT. Generally, In DMS materials the delocalized conduction bandelectrons and valence Neodymium Magnets band holes interact with the localizedmagnetic moments associated with the d or f electrons in magneticatoms. However, those materials such as ZnO thin film with 5%Scdoping, HfO2 thin film, CaB6,SrB6 and radiated graphite allcontain no partially filled d or f shells of transition metalor rare earth element, but exhibit Tc above room temperature.Considering that all of them are film materials ,and ,it is wellknown that the film materials have larger ratio of area andbulk ,therefore the intrinsic defects during the growth of thinfilm would have great influence on there physical properties.As for CaB6 and SrB6, it has been proved experimentally that themagnetic moment per formulas in thin film is two or four timelarger in orders of magnitude than that in the single crystalor polycrystalline materials. And the theoretical calculationsrelated to it proved that the B6 vacancy in CaB6 carries a magneticmoment of 2.4μB. As for HfO2, it has been reported that the thinfilm exhibits ferromagnetism with Tc above 500K, but no in thebulk materials. And calculation on HfO2 proved that the Hfvacancy in HfO2 exhibits a magnetic moment Neodymium Magnets of 3.5μB, and themagnetic moments are ferromagnetic coupled.
As for graphite, ithas been proved experimentally that the nonmagnetic graphitewould exhibit ferromagnetism after it is radiated with http://www.999magnet.com/ highenergy particles. And calculation proved that vacancy or thecomplex of vacancy and hydrogen carries magnetic moment. As forZnO, it is well known that ZnO is non-ferromagnetic. Andtheoretical calculation showed that ZnO with one Zn atomsubstituted with Sc exhibited no ferromagnetism. Defects insimple oxides that trap two electrons or two holes are known tohave triplet ground state or low-lying triplet excited state.The role of the dopant is to stabilize the triplet ground state.It will produce Zn vacancy in (Zn0.95Sc0.05)O when Zn+2is substitutedwith Sc+3,therefore Zn vacancy will play an important role in ZnOthin film with Sc doping .we theoretically studied the effectof Sc on the VZn so as to search for the possible ferromagneticorigin.Firstly, I studied the influence of the intrinsic defectssuch as VO= and VZn on the magnetism of ZnO thin film. And I got1.8μB/VZn in Zn15O16, but not in Zn16O15. Secondly, we studied theeffect of Sc on the magnetism.
We performed spin-polarizedelectronic calculation on the supercell Zn14Sc1O16, whichcontains Sc and VZn. We got 1.0μB/VZn. In order to simulateactual doping :two Sc atoms will introduce one VZn, We got netmagnetic moment of 0.4μB/VZn, which agrees well with theexperimental result 0.2-0.3μB/VZn. Thirdly, we studied thechange of magnetic moment with the Neodymium Magnets distance of Sc and VZn. Wegot that: it results no change on the magnetism moment, butthe redistribute of magnetic moment on the neighboring atoms.We also calculated the effect of Sc on the formation energyof VZn. We got that: With the introduction of Sc, the formationenergy of VZn reduced apparently, which means Sc favors theformation of VZn .We also calculated and compared the totalenergy of Zn14Sc1O16 with the magnetism moment coupledferromagnetically and antiferromagnetically. We got that theferromagnetic configuration has smaller energy. Then we drawa conclusion that: VZn is the origin of ZnO thin film with 5%Sc doping.
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