tungsten, manganese, cyanide

作者:LEE JinWuk;LIM KwangSoo;YOON JungHee;RYU DaeWon;KOO

BongHo;KOH EuiKwan;HONG ChangSeop;
关键词:tungsten, manganese, cyanide, crystal structure, single-

chain magnet
单位:Department of Chemistry, Research neodymium price Institute for Natural

Sciences, Korea University, Seoul 136-713, Korea;Nano-Bio System

Research Team, Korea Basic Science Institute, Seoul 136-713,

Korea;
摘要:Reaction of unique [W(CN)6(phen)]- http://www.999magnet.com/products/142-neodymium-price with a magnetically

anisotropic Mn Schiff base yielded a WⅤ(5d)-MnⅢ(3d) bimetallic

compound with a linear chain structure. The magnetic properties

of the chain complex feature a ferrimagnetic behavior as well as

slow magnetic relaxation typical for a single-chain magnet.

作者:毕延芳,严陆光
关键词:门人:8496,日月:5273
单位:Graduate School,University of Science and Technology of

China, Beijing





,Institute of Electrical Engineering,

Academia Sinica, Beijing
摘要:<正> The force-free magnets are those in which the current

density J is everywhere parallel to the field H, i.e. J=αH,

where a is a scale function called force-free factor or

function.Therefore the Lorentz force f is equal to zero, since f=

μJ×H=0.However, from the virial theorem of mechanics it can be

verified that

force-free magnets are those

作者:毕延芳,严陆光
关键词:门人:8496,日月:5273
单位:Graduate School,University of neodymium price
http://www.999magnet.com/products/142-neodymium-price Science and Technology of

China, Beijing





,Institute of Electrical Engineering,

Academia Sinica, Beijing
摘要:<正> The force-free magnets are those in which the current

density J is everywhere parallel to the field H, i.e. J=αH,

where a is a scale function called force-free factor or

function.Therefore the Lorentz force f is equal to zero, since f=

μJ×H=0.However, from the virial theorem of mechanics it can be

verified that

INTRODUCTION The development of alloys

作者:李东升,彭会子,孙津生,张玉权,鞠克昌
关键词:金属学会:7478,金子:3505,概要:3104,讲演:3068,日本:3000,特许

:954,大会:904,公报:902,春期:820,东京:716
单位:Tianjin Metallurgical Research Institute





,Tianjin

Metallurgical Research Institute





,Tianjin Metallurgical

Research Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Institute





,Tianjin Metallurgical Research

Institute





,Tianjin Metallurgical Research Institute
摘要:<正> Ⅰ. INTRODUCTION The development of alloys with

improved magnetic properties, especially with high (BH)_(max)

value has up to the present been the main topic for research of

magnet materials. Kaneko suggested that samples of Fe-Cr-Co alloy

may be swaged after field treatment so that the precipitated

particles from supersaturated solution would be elongated and

aligned more perfectly. The magnetic values may be raised by this

treatment, but the samples obtained by such process can only be

in the form of small bars, and moreover, the process is too

complex to be used for production in quantity.

epartment of Physics, Nanjing University

作者:赵骥万,王广厚,张健,王桂琴,张世远,刘长清,翟宏如,陈培林,宋后定
关键词:穆斯堡尔谱:4865,计算机分析:3841,南京大学:3769,科研组:3086,

日纽:2934,大学学报:2754,衬比:2616,合一:2458,比价:2326,光明:1824
单位:Department of Physics, magnetic materials
http://www.999magnet.com Nanjing University





,Department

of Physics, Nanjing University





,Department of Physics,

Nanjing University





,Department of Physics, Nanjing

University





,Department of Physics, Nanjing University





,

Department of Physics, Nanjing University





,Department of

Physics, Nanjing University





,Research Institute of Applied

Magnetics of Southwest China





,Research Institute of Applied

Magnetics of Southwest China
摘要:<正> Rare earth cobalt permanent magnetic alloys are a new

generations of permanent magnets developed in the last decade, of

which SmCo_5 permanent magnets are the best developed and have so

far been the most widely used Re-Tin material. Its magnetization

reversal mechanism is nucleation. The magnetization reversal

undergoes several proceases such as nucleation, growing,

detaching and pinning at grain boundaries, etc. For sintered

magnet, in order to attain high coercive force, not only high

nuclea-

作者:何国柱;
关键词:洁牙:6789,广厅:4385,合肥:3641,多梦:3067,切口:2631,国名:2254
单位: Nankai University,
摘要:<正> Ⅰ. INTRODUCTION The problem of focusing electron beams by periodic magnetic fields has been studied by many Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets authors, e.g., Brewer, Clogston and Heffner, and Mendel, Quate and Yocum. In their studies, it has been assumed that the electron beams are emerging from cathodes completely shielded from the magnetic field. Chang and Mendel have extended these studies to cover the


作者:袁重华,潘崇言,金瑞湘,吴灵葳
关键词:知心:6355,八国:5829,护国:5062
单位:Research Institute of Iron and Steel, Ministry of Metallurgy









,Research Institute of Iron and Steel, Ministry of Metallurgy









,Research Institute of Iron and Steel, Ministry of Metallurgy









,Research Institute of Iron and Steel, Ministry of Metallurgy
摘要:<正> X-ray diffraction study, together with magnetic measurements, was made on liquidphase sintered permanent magnets of the RCo_5 type (R=Sin, Sm_(0.5) Pr(0.5), or MM(0.6) Sm(0.5)). It was found that the sintered samples invariably possessed a skin layer of about 0.3 mm in thickness. This layer and the core of the sample, therefore, had te be studied separately, magnetic measurements being made only on the core. In comparison with the core, the skin layer proved to have a more complex structure. As far as composition is concerned, the akin material had a higher R-content and a lower Co-content. At an overall Co-content of about 63% by weight: the sintered core had a maximum intrinsic coercive force and exibited only a single metallic phase, i.e., the RCo_5-type intermetallic compound with CaZn_5 structure. No evidence for the presence of any R_2Co_7 or R_2Co_17 phase was detected in the diffraction patterns. The relative amount of the liquid-phase siniering aid in the mixed powder before sintering was varie


关键词:NdFeB;;rare earth permanent magnet;;microstructure
摘要:<正> An addition of Nb up to 2 at.-% into(Nd,Dy)-(Fe,Co)-B alloy causes the formation ofdendrite Fe_2Nb and the precipitates in hard magnetic grains.Both increases withincreasing Nb content.During sintering,part of Fe_2Nb dissolves within the 2:14:1 grains,and the Fe_2Nb along grain boundaries hinders the growth of 2:14:1 grains.During an-nealing,the dissolved Nb in(?)-phase precipitates out,and this nearby the grain boundarydiffuses into Nd-rich phase to form new granular Fe_2Nb and to increase the Nb contentin Nd-rich phase,this results in a precipitate-free zone in the(?)-grain near Nd-rich phase.

Nd-Fe-B magnet

作者:黄钢祥;徐庆镇;高惠民;余善富;华宏慈;王葛亚;
关键词:coercivity;;Nd-Fe-B magnet
单位:Shanghai Iron and Steel Research Institute Shanghai,200940,China.,Shanghai Iron and Steel Research Institute,Shanghai,200940,China.,Shanghai Iron and Steel Research Institute,Shanghai,200940,China.,magnetic materials
http://www.999magnet.com Shanghai Iron and Steel Research Institute,Shanghai,200940,China.,Shanghai Institute of Metallurgy,Academia Sinica,Shanghai,200050,China.,Shanghai Institute of Metallurgy,Academia Sinica,Shanghai,200050,China.,
摘要:<正> The microstructures of melt-spun Nd_135-Fe_81.74B4.76 ribbons have been investigated bymeans of X-ray diffraction,Mossbauerspectroscopy and HREM.Experimental resultsshow that optimal magnetic properties of the bond-ed magnet can be obtained by melt-spun alloys atwheel velocity of 24m/s,the microstructure ofwhich was single phase Nd_2Fe_(14)B crystallites,andno other phases,such as Nd-rich,B-rich or x-Fephase,were present.It is considered that the highintrinsic coercivity ~iH_c can be attributed to the sin-gle-domain behaviour of Nd_2Fe_(14)B crystallitephase.

Rare earth-iron-nitride;;Permanent magnet

作者:杨俊;周寿增;张茂才;马德青;李佛标;王润;
关键词:Rare earth-iron-nitride;;Permanent magnet;;Stability
单位:Department of Materials University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,Department neodymium prices
http://www.999magnet.com/products/142-neodymium-prices of Materials,University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,Department of Materials,University of Science and Technology Beijing,Bering 100083,China,
摘要:<正> The effects of the partial substitution of element M(M=Cr,V,Mn,x=0.05;Zr,Ga,x=0.017;Si,x=0.15;Co,x=0.10)for Fe in samarium-iron-nitride Sm_2(Fe_(1-x)M_x)_(17)N_y compounds on their stabilitiesand Curie temperatures have been studied.It is found that Co,Ga can raise the Curie temperature of thecompounds.The initial decomposition temperatures cannot be raised significantly by all the studied elementsexcept Co.The result contradicts the formation enthalpy consideration.The final decomposition tempera-tures can be raised by all of the substitution elements.The effects of atmospheres on their decomposition be-havior were also studied.The results show that oxidation is the major reason for magnetic deterioration ofthe powder heated in air.Compared with nitrogen atmosphere,argon or vacuum helps to delay the decompo-sition of the compounds.

Magnetic properties;;Sintered magnets

作者:刘金芳;罗河烈;潘树明;聂向富;侯登录;
关键词:Magnetic properties;;Sintered magnets
单位:Magnetism Laboratory Institute of Physics,Chinese Academy of Sciences,Beijing 100080,China,Magnetism Laboratory,Institute of Physics,Chinese Academy of Sciences,Beijing 100080,China,General Research Institute for Non-Ferrous Metals,Beijing,China,Department of Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Physics,Hebei Normal University,Shijiazhuang City,Hebei Province,China,Department of Physics,Hebei Normal University,Shijiazhuang City,Hebei Province,China,
摘要:<正> The magnetic properties of Nd_(16)Fe_(77)B_7 and Nd_(16)Fe_((61-x))Co_(16)Ga_xB_7(x=0,1,2,4,7)have been measured.Itis found that the remanent magnetization(Br),maximum energy product(BH)_(max)and the Curie temperature(T_c)decrease with the increase of Ga content.The coercive force(He)increases with the increase of Ga contentwhen x is less than 2,but decreases when x>2.At x=2,the coercive force reaches its maximum value.It is alsofound in all the samples investigated that there is a linear relationship between H_c~(1/2)and T~(2/3),which can not beexplained by Gaunt's wall barrier model.The temperature dependence of the calculated values of H_v and(4bf)has been discussed.

Department of Rare Earth Alloy Materials

作者:黄付贵;李东;吕其春;
关键词:日息:8496,巴山:5273
单位:Department of Rare Earth Alloy Materials Iron & Steel Research Institute,Guangzhou 510640,China,Central Iron & Steel Research Institute,Beijing,Central Iron & neodymium prices
http://www.999magnet.com/products/142-neodymium-prices Steel Research Institute,Beijing,
摘要:<正> The process of the epoxy-bonded Sm_2TM_(17) magnets includes:(1)after melting,the ingots are treatedby solid soluiion,and then aged and pulverized;(2)the obtained alloy powder is mixed with epoxy resin bind-er;(3)the mixture is pressed in a magnetic field;(4)the compacts are cured.When theSmCo_(4.9)Fe_(2.7)Cu_(0.54)Zr_(0.13) alloy is heat treated and pressed with optimum pressing parameters,the high qualitybonded magnets with B_r=8250 G,_iH_c=13000 Oe,and(BH)_(max)=16MGOe can be obtained.The stabilityof the magnets is studied also.The irreversible loss of O.C.(open circuit)remanence B_r in the temperaturerange between 25 and 150℃,is less than 4%.The average temperature coefficient at temperatures between 25and 70℃ is-0.03%/℃.The magnets obtained have heat resistance up to 130℃ even in long-term service,and have good corrosion resistance in acid,alkali and salt solutions.

Magnetization and demagnetization cur

关键词:花毛:10000
摘要:<正> Magnetization and demagnetization curves and hysteresis loops applied different magnetizing.fields magnetic materials
http://www.999magnet.com insintered Nd-Fe-B and Nd-Dy-Fe-B magnets from thermally demagnetized and dc field-demagnetizedstates were investigated at temperatures of up to 150℃.The first-quadrant remagnetization curves and thecurves of coercive forces _MH_C versus rernagnetizing fietds H_m from dc field-demagnetized state at roomtemperature show a step around magnetizing field as absolute value of the maximum intrinsic coercivity.Thesteps of _MH_C-H_m curves shifted to lower remagnetizing fields and the shapes of magnetization curveschanged from step type to precipitous type when temperature went up to 100～150℃ or after the specimenwas thermally demagnetized at a temperature higher than the Curie temperature.The steep rise of kneecoereivity with increasing magnetizing field is behind that of _MH_C.Note that the magnetic hardening insintered Nd-Fe-B magnets is controlled by pinning of domain walls.

metal materials; crystal growth; microstructures; laser rapid

作者:潘晶,刘新才
关键词:metal materials; crystal growth; microstructures; laser rapid solidification; magnetic materials; neodymium compounds; magnetic domains;rare earths
单位:Department of Physics, Faculty of Sciences, Ningbo University, Ningbo 315211, China








,Department of Physics, Faculty of Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets Sciences, Ningbo University, Ningbo 315211, China
摘要:To research the solidification behavior and microstructures of a laser remelting/solidification layer on anisotropic Nd_(15)Fe_(77)B_(8 )sintered magnets with their magnetization direction parallel to X, Y, Z-axis respectively, their surfaces (parallel to XOY plane) were scanned by 5 kW Roffin-Sinar 850 type of CO_(2) laser along Y axis. The rapid solidification of the molten alloy in the layer results in three distinct zones. The transition zone close to the unmolten portion of a magnet (substrate), consists of the columnar Nd_(2)Fe_(14)B phase (matrix), the 10.0%~15.1% dendrite primary iron phase dispersing in the matrix, and the Nd-rich phase along Nd_(2)Fe_(14)B grain boundaries. The columnar crystal zone in the middle of the layer consists of the long columnar Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. And the dendrite crystal zone near the free surface of the layer consists of dendrite Nd_(2)Fe_(14)B grains and their grain boundary Nd-rich phase. When the laser scanning velocity is lower, the growing direction of the microstructures in the layer tends to the laser scanning direction step by step. When the velocity is not lower than 25 mm·s~(-1), the laser remelting/solidification layer thins and the columnar crystal zone comprises almost the whole layer. Under this condition, on the substrate with its magnetization direction along X or Y-axis respectively, the columnar Nd_(2)Fe_(14)B grains in the layer grow in the direction of Z-axis (that is their long-axis along Z-axis), their alignment of the easy magnetization axis [001] is parallel to the magnetization direction of the substrate correspondingly; but on the substrate with its magnetization direction along Z-axis, the columnar Nd_(2)Fe_(14)B grains in the transition zone grow at an angle of 30°~50° between Z-axis and their long-axis. And the columnar Nd_(2)Fe_(14)B grains in the columnar crystal zone gradually tend to the Z-axis,and their easy magnetization axis [001] arrange in the range of 0°~360° of the plane perpendicular to their long-axis.

作者:连利仙,刘颖,高升吉,涂铭旌
关键词:metal materials; Zirconium; nanocomposite magnets; microstructure; magnetic properties; rare earths
单位:College of Materials Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets Science & Engineering, Sichuan University, Chengdu 610065,China








,College of Materials Science & Engineering, Sichuan University, Chengdu 610065,China








,College of Materials Science & Engineering, Sichuan University, Chengdu 610065,China








,College of Materials Science & Engineering, Sichuan University, Chengdu 610065,China
摘要:Five kinds of bonded magnets with compositions of Nd_(10.5)Fe_(78.4-x)Co_5Zr_xB_(6.1)(atom percentage x=0,1.0,(1.5),2.0,2.5)were prepared by rapid quenching, post heat treatment and mould-pressing.The microstructure and crystallization behavior were studied by X-ray diffraction (XRD), differential thermal analysis (DTA) and atomic force microscopy (AFM). The results suggest that high content of Zr can increase the glass formation ability (GFA) of alloys. When the content of Zr is controlled at a certain level, Fe_2Zr with high melting point is formed in the alloys, and grain size is reduced consequently. At the same time, because of Zr addition, the coercivity and squareness of demagnetization loop are obviously improved, and the energy product is accordingly increased. As a result, optimal magnetic properties of Nd_(10.5)Fe_(78.4-x)Co_5Zr_xB_(6.1)(B_r=0.659 T,H_(cj)=628 kA·m~(-1),H_(cb)=419 kA·m~(-1),(BH)_m=73 kJ·m~(-3)) are obtained when x=2.

Penning trap,linear programming,magnet design,nonlinear

作者:吴巍;何源;马力祯;黄文学;夏佳文;
关键词:Penning trap,linear programming,magnet design,nonlinear

optimization methods,pattern search
单位:Institute of Modern Physics,Ball Neodymium Magnets
http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php Chinese Academy of

Sciences;Graduate University of Chinese Academy of Sciences;
摘要:A Penning trap system called Lanzhou Penning Trap(LPT) is

now being developed for precise mass measurements at the

Institute of Modern Physics(IMP).One of the key components is a 7

T actively shielded superconducting magnet with a clear warm bore

of 156 mm.The required field homogeneity is 3 × 10-7 over two 1

cubic centimeter volumes lying 220 mm apart along the magnet

axis.We introduce a two-step method which combines linear

programming and a nonlinear optimization algorithm for designing

the multi-section superconducting magnet.This method is fast and

flexible for handling arbitrary shaped homogeneous volumes and

coils.With the help of this method an optimal design for the LPT

superconducting magnet has been obtained.

nanocomposite;ttrium substitution;glass forming

作者:龙风;施毅;刘方;倪志鹏;
关键词:quench detection,quench protection,balancing-bridge
单位:Institute of Plasma Physics,Chinese Academy of Sciences;
摘要:A NbTi 7 T superconducting magnet with a 338 mm bore system

was rebuilt and the first experiment was carried out in

Jan.2009.The balancing-bridge method used for the quench

detection system is analyzed and an improvement of the principle

of balancing-bridge conformation is given.The inductances of the

coils are calculated to estimate the proportion of the bridge

arms.The appropriate parameters are selected for the balancing-

bridge.


作者:陈治安;罗骥;隋延力;郭志猛;
关键词:nanocomposite;ttrium substitution;glass forming y

ability;residual amorphous phase;squareness;rare earths
单位:Institute of Powder Metallurgy,Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php University of Science and

Technology Beijing;State Key Laboratory for Advanced Metals and

Materials,University of Science and Technology Beijing;
摘要:The phase evolution,microstructure and magnetic properties

of Nd9-xYxFe72Ti2Zr2B15(x=0,0.5,1,2) nanocomposite ribbons were

investigated.It was found that substitution of Y enhanced glass

forming ability of the over-quenched ribbons and stabilized the

amorphous phase during post annealing treatment.Appropriate

content of Y substitution effectively refined the microstructure

and enhanced the remanence of the annealed samples.The residual

amorphous intergranular phase in the annealed sample improved the

squareness of loops,resulting in enhanced maximum energy

product.The optimum annealing treatment significantly improved

magnetic properties of the Y substituted ribbons.Best magnetic

properties,Jr=0.78 T,Hci=923.4 kA/m,(BH)max=98.5 kJ/m3 were

obtained from Nd8YFe72Ti2Zr2B15 ribbon spun at Vs =4 m/s,and

annealed at 700 °C for 10 min.

sintered NdFeB magnets;multilayer ceramic

作者:A.Ali;A.Ahmad;K.M.Deen;
关键词:sintered NdFeB magnets;multilayer ceramic

coating;permeable defects;rare earths
单位:Department of Metallurgical & Materials Engineering

University of Engineering & Block neodymium magnet
http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php Technology;Department of Metallurgy

and Materials Engineering CEET,University of the Punjab;
摘要:Sintered NdFeB magnets have complex microstructure that

makes them susceptible to corrosion in active environments.The

current paper evaluated the anticorrosion characteristics of

multilayer titanium nitride ceramic coating applied through

cathodic arc physical vapour deposition(CAPVD) for protection of

sintered NdFeB permanent magnets.The performance of ceramic

coating was compared to the electrodeposited nickel coating

having a copper interlayer.Electrochemical impedance

spectroscopy(EIS) and cyclic polarization in simulated marine

environment were employed to determine the rates of coatings

degradation and passivation behaviour respectively.The coating

morphologies and surface chemistry were studied with scanning

electron microscope(SEM).X-ray diffraction(XRD) was used for

identification of component phases in the coatings and the

substrate.The results showed that the polarization resistance of

ceramic coating increased with the exposure time.The rate of

degradation of Rp for the ceramic coating had an extraordinary

negative slope followed by a stable duration,before declining

towards the coating failure.In comparison the nickel coating with

copper interlayer degraded sharply.The vapour deposited ceramic

coating was found to have permeable defects that tended to "re-

passivate" during exposure providing prolonged corrosion

protection to the NdFeB substrate.The magnetic properties were

unaffected and remained at par with the nickel coating having

copper interlayer.

Rhodotron, deflecting magnets, magnetic sector field,

作者:Farshid Tabbakh;
关键词:Rhodotron, deflecting magnets, magnetic sector field,

ANSYS11
单位:Institute of Nuclear Science and neodymium prices
http://www.999magnet.com/products/142-neodymium-prices Technology,School of

Irradiation Application,Atomic Energy Organization of Iran;
摘要:The beam trajectory in the first deflecting magnet of

"Rhodotron" TT200 has been analyzed precisely by both optical and

simulation methods. We found discrepancies between these two

methods at the order of (10-3) for the slit distance and

deflecting radius and at the order of (10-4) for the magnetic

flux density. The main goal of the paper is beam focusing,

considering the angular and momentum dispersion of the particles

for the magnet designed by ANSYS.

magnetic anisotropy; spin-orbit coupling

作者:R.Skomski;D.J.Sellmyer;
关键词:magnetic anisotropy; spin-orbit coupling; crystal-field

interaction; interstitial modification; permanent magnets; rare

earths
单位:Department of Physics and Astronomy, NCMN, University of

Nebraska;
摘要:Rare-earth intermetallics Neodymium Magnets
http://www.999magnet.com/products/110-sintered-neodymium-magnets such as Nd2Fe14B and Sm-Co are

widely used as high-performance permanent magnets, because they

combine high magnetocrystalline anisotropy with reasonable

magnetization and Curie temperature. The anisotropy is a combined

effect of spin-orbit coupling and electrostatic crystal-field

interactions. The main contribution comes from the rare-earth 4f

electrons, which are well-screened from the crystalline

environment but exhibit a strong spin-orbit coupling. In this

limit, the magnetocrystalline anisotropy has a very transparent

physical interpretation, the anisotropy energy essentially being

equal to the energy of Hund's-rules 4f ion in the crystal field.

The corresponding expression for the lowest-order uniaxial

anisotropy constant K1 is used to discuss rare-earth

substitutions, which have recently attracted renewed interest due

to shifts in the rare-earth production and demand. Specific

phenomena reviewed in this article are the enhancement of the

anisotropy of Sm2Fe17 due to interstitial nitrogen, the use of

Sm-Co magnets for high-temperature applications, and the

comparison of rare-earth single-ion anisotropy with other single

-ion and two-ion mechanisms.

Researches on Testing System for Gimbal’s Micro-torque of Steering Tube

Researches on Testing System for Gimbal’s Micro-torque of Steering Tube

 With the rapid development of modern automobile industry, people have higher requirements of its dynamics, comfort and security. Security has become the critical focus in the tendency of China’s automobile technology development. Rover750 steering tube is designed based on the concept of passive safety technology. The design of its collapsible energy-absorbing structure and deformation element in the tube with gimbal can effectively reduce impact of the steering wheel to the drivers on emergency, which makes the steering system more safe.One of performance evaluations to this new type of steering tube is to neodymium prices measure its gimbal’s micro-torque. Gimbals can move in two different planes. When measured in one plane, the gimbal must be kept stable in the other one. The traditional measurement method keeps the gimbal stable by spring hook, however, it introduces variable outside force and produces errors to the results which cannot be eliminated.Two new practical methods named Elbow Method and Magnetic Suspend Method are presented. The former one keeps the gimbal stable directly by the force sensor, which can endure a certain range of shear force and be non-sensitive to this force. Similar to Maglev Train, the other method keeps the gimbal by magnetic repulsion. Both of the methods achieve the goals and avoid the disadvantages of traditional method.The http://www.999magnet.com/products/142-neodymium-prices automatic testing system of gimbal’s micro-torque according to the Elbow Method is discussed in detail. Firstly, the mechanical characteristics of the system is described, which can move freely in three different coordinates and avoid clamp locking when measured. The testing system controls the electromotor with the core of industrial controlcomputer to realize the completely automatic testing of gimbal’s micro-torque depended on high precision force sensor, signal processing circuit, and PCL-818L data acquisition card of ISA bus. Compared with the traditional method, the testing data proves the validity and effectiveness of Elbow Method, and high precision, efficiency and powerful data operation and processing of the system. Since being put into production use, the system is always in good state and promotes the production efficiency greatly.The software is also discussed, especially on its parts of precise timing, digital data filtering, real-time curve drawing and automatic interface response in the VC programming. 更多还原

The Study of Dispersion Behavior of Barium Ferrite and Its Effect on Magnetic Properties

The Study of Dispersion Behavior of Barium Ferrite and Its Effect on Magnetic Properties

Barium ferrite is widely used in permanent magnet, magnetic recording and stealth material etc. In order to obtain good properties, the particles of barium ferrite tend to micronization. The agglomeration becomes one of the main problems which limit the application of barium ferrite. In this thesis, the dispersion behavior of barium ferrite and molding of anisotropy barium ferrite in magnetic field were studied. The results of the study are as follows:1. The interaction of barium ferrite particle in the liquid was calculated. Block neodymium magnet The result indicates that the force of Van der Waals and magnetism attraction between the particles were the most reason, which result in agglomeration of the barium ferrite particles in the liquid. The magnetism attraction was the main factor that causes the particle agglomeration when the barium ferrite particle is more that 0.5μm.2. Electrostatic dispersion of barium ferrite particles in the air was discussed. The square of the charging field intensity is inversely proportional to the critical radius of barium ferrite particle.3. The effects of dispersants and other parameters on the dispersion in the liquid were examined. The results show that the dispersion of the particle barium ferrite will get better with the increase of ball-milling time and tend to be stabilization after slurry was milled for 16h. The sodium dodecyl sulfate and polyethylene glycol compound dispersant is the best. http://www.chinamagnets.biz/Neodymium/Block-neodymium-magnet.php PH value also has effect on the dispersion, when slurry at pH 10, the dispersion was improved. The analysis of XRD suggested that the dispersants will not result in the change of the component of the barium ferrite.4. Molding of anisotropy barium ferrite in magnetic field was investigated. The effect of dispersion, intensity of magnetic field and temperature of sinter were discussed. The results showed that the anisotropy of barium ferrite will be better while adding dispersant in the slurry and will gain excellent anisotropy barium ferrite when 更多还原

The Design of Aerocraft Electric Anti-skid Braking Controller

The Design of Aerocraft Electric Anti-skid Braking Controller

 Aerocraft electric anti-skid braking system is an important part of multi-electric aerocraft, in which braking controller is the most important part. The traditional analog controller is replaced by the digital controller and the hydraulic actuator is replaced by the electromechanical actuator, which improves the aerocraft braking efficiency and performance greatly. According to the aerocraft electric anti-skid braking system’s project request, a practical aerocraft electric anti-skid braking controller is designed, the Ball Neodymium Magnets design of the controller hardware and software is introduced in detail and the control stragety is studied in depth.Slip ratio control variable is studied. The paper analyses the relationship between slip ratio and attachment coefficient in detail, aerocraft wheel’s force and the anti-skid braking principle. The braking controller is composed of the anti-skid controller and the motor drive controller. The two redundancy actuator is put forward, which is the structure of four brushless DC motors driving four ball screws. The structure of actuator, cross-sectional view and triple geared drive equipment is introduced, and the structure and control principle of permanent-magnet brushless DC motor is analysed. In hardware designing, TMS320F2812 and its peripheral circuit make up the velocity capturing circuit. Anti-skid controller controls slip ratio error and exports http://www.chinamagnets.biz/Neodymium/Ball-Neodymium-Magnets.php braking pressure signal. In the motor drive controller, current sampling circuit, overcurrent protecting circuit, pressure adjusting circuit and signal insulating circuit are made up of TMS320F2812 and its peripheral circuit. CPLD ( EPM7128AE) is employed to deal with the brushless DC motor’s rotor postion signal in order to realize commutation. Three-phase full bridge inverting circuit is composed of gate driven IC IR2130 and its peripheral circuit to drive brushless DC motor. In software designing, C language and assembly language together is adopted to control system.The three closed loop strategy with slip ratio loop as the outer one, pressure loop as the middle one and current loop as the inner one is used. Conventional PID is still used to adjust error in control algorithm and is improved.The strategy of the fuzzy control adjusting PID is put forward. The model of the convertional PID control and the fuzzy control are based. According to the simulation curve, system response speed is quicken, over regulation measurement is 更多还原