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Magnetic properties and structure of very thin permalloy films

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Journal of university of science and {2. Beijing 2004年第3期11卷 225-229页

作者： Guanghua Yu Haifeng Li Tao Yang Fengwu Zhu materials science and {2. school, university of science and technology Beijing, Beijing 100083, china Mat. Sci. and Eng. Sch. Univ. of Sci. and Technol. Beijing Beijing 100083 China

In order to study the magnetic properties and structure of very thinpermalloy films, Ni_(81)Fe_(19) films of 12.nm in thickness were prepared by different instrumentsat an ultrahigh base vacuum and a lower base vacuum. The anisotropic magnetoresistance coefficients(ΔR/R) of Ni_(81)Fe_(19) (12.nm) films reached 1.6 % and 0.6 %, and the coercivities were 12. and334 A/m, respectively. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) were usedto study the structure and surface chemical state. The experimental results show that the filmsprepared at the ultrahigh base vacuum have a smoother surface, a bigger grain size and a denserstructure with fewer defects than those prepared at the lower base vacuum.

关键词： NiFe film anisotropic magnetoresistance (AMR) coercivity structure

Effect of rare-earth element Sm on the corrosion behavior of Mg-6Al-1.2.-0.9Nd alloy

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Rare Metals 2010年第6期29卷 557-560页

作者： LI Quan’an,LI Xiaofeng,ZHANG Qing,and CHEN Jun school of materials {2. and engineering,Henan university of {2. and technology,Luoyang 471003,china school of materials {2. and engineering Henan University of Science and Technology Luoyang China

The effect of Sm（0 wt.%-2.wt.%） addition on the corrosion behavior of Mg-6Al-1.2.-0.9Nd alloy in 3.5 wt.% NaCl solution has been studied by static corrosion tests,corrosion morphology observation,corrosion scale and microstructure *** results show that,with the increasing of Sm content,the corrosion rate of the alloy decreases at first,then increases and reaches the valley at 0.5 wt.% *** reason is that the proper content of Sm addition can refine the precipitates and make the component and microstructure uniform,and therefore,it remarkably improves the corrosion resistance of the alloy.

关键词： magnesium alloys samarium corrosion behavior microstructure

In Situ Studies of Deformation and Fracture in Sputtering Copper Film

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International Journal of Minerals,Metallurgy and materials 2000年第1期14卷 38-41页

作者： Jinxu Li Yimin Zeng Yanbin Wang Wuyang Chu materials science and {2. school, university of science and technology Beijing, Beijing 100083, china materials science and {2. school University of Science and Technology Beijing Beijing 100083 China

Nanocrystalline copper films were prepared by sputtering and then in situ straining experiments were performed using a trans- mission electron microscope. Macroscopically, these copper films exhibited very low ductili... 详细信息

关键词： in situ straining, deformation fracture nanocrystalline copper film

Nonlinear Theory on Dynamic Controlling Interface Patterns DuringSolidification of a Dilute Binary Alloy

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International Journal of Minerals,Metallurgy and materials 1999年第4期13卷 253-258页

作者： Zidong Wang Hanqi Hu(Material science and engineering {2., university of science and technology Beijing, Beijing 100083, china) Material science and engineering {2. University of Science and Technology Beijing Beijing 100083 China

In non-equilibrium nonlinear region, the nonlinear equations of time dependence of perturbation amplitude at the solid/liquidinterface during solidification of a dilute binary alloy are established on the base of assuming that there is local equilibrium at the solid/liquid interface and considering that curvature, temperature and composition at the solid/liquid interface which are related to the perturbation amplitude are nonlinear. As a result, patterns at the solid/liquid interface during solidification process, which is from nonsteadystate to steady state can be controlled by these nonlinear equations.

关键词： nonlinearity solidification, dilute binary alloy, dynamic control

Bonded Terfenol-D composites with low eddy current loss and high magnetostriction

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Rare Metals 2010年第6期29卷 579-582页

作者： TIAN Jianjun,ZUO Zhijun,PAN De’an,and ZHANG Shengen school of materials {2. and engineering,university of {2. and technology Beijing,Beijing 100083,china school of materials {2. and engineering University of Science and Technology Beijing Beijing China

Bonded Terfenol-D composites,with high electrical resistivity and low eddy current loss,can be used in an alternating magnetic field with high ***,the nonmagnetic binder impairs the magnetostriction of the *** achieve high magnetostriction and low eddy current loss,the mixture of the alloy powder and binder was compressed at low pressure in an oriented magnetic *** this,the aligned samples were recompressed by cold isostatic pressing（CIP）.Besides,the effect of particle size on the magnetostriction of the bonded Terfenol-D composites was also *** results showed that the bonded Terfenol-D composites had excellent magnetostriction when the particle size was 50-80 μ*** oriented magnetic field and CIP could improve the magnetostriction of the bonded composites,which reaches 102.×*** bonded Terfenol-D composites had good compact structure and high density（7.2. g/cm3）.The magnetic loss of the bonded Terfenol-D composites was 192.mW/cm3 at a frequency of 100 kHz in a magnetic field of 960 A/m,which was about one third of that of casting Terfenol-D alloys.

关键词： composites Terfenol-D magnetostriction eddy current losses density

High-temperature oxidation behavior of Al_2._3/TiAl matrix composite in air

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science china(Technological sciences) 2009年第5期52卷 1273-1282页

作者： AI TaoTao1,WANG Fen2.& FENG XiaoMing1 1 Department of materials science and {2.,Shaanxi university of technology,Hanzhong 72.003,china 2.school of materials science and {2.,Shaanxi university of science and technology,Xi’an 71002.,china 1. Department of materials science and {2. Shaanxi University of Technology Hanzhong 723003 China 2. school of materials science and engineering Shaanxi University of Science and Technology Xi’an 710021 China

The oxidation behavior of Al2.3/TiAl in situ composites fabricated by hot-pressing technology was in-vestigated at 900℃ in static *** results indicate that the mass gains of the composites samples decrease gradually with increasing Nb2.5 content and the inert Al2.3 dispersoids effectively increase the oxidation resistance of the *** higher the Al2.3 dispersoids content,the more pro-nounced the *** primary oxidation precesses obey approximately the linear laws,and the cyclic oxidation precesses follow the parabolic *** oxidized sample containing Ti2.lN and TiAl phases in the scales exhibits excellent oxidation *** oxide scale formed after exposure at 900 ℃ for 12. h is multiple-layered,consisting mainly of an outer TiO2.layer,an intermediate Al2.3 layer,and an inner TiO2.Al2.3 mixed *** the outer layer to the inner layer,TiO2.Al2.3 mixed layer presents the transit of Al-rich oxide to Ti-rich oxide mixed *** the substrate,cross-section micrograph shows a relatively loose layer,and micro-and macro-pores remain on this layer,which is a transition layer and transferres from Al2.3+TiO2.scale to *** thickness of oxide layer is about 2. μ*** is also found that continuous protective alumina scales can not be observed on the surface of oxida-tion *** ions diffuse outwardly to form the outer TiO2.layer,while oxygen ions transport inwardly to form the inner TiO2.Al2.3 mixed *** long-time intensive oxidation exposure,the internal Al2.3 scale has a good adhesiveness with the outer TiO2.*** obvious spallation of the oxide scales *** increased oxidation resistance by the presence of in situ Al2.3 particulates is at-tributed to the enhanced alumina-forming tendency and thin and dense scale ***2.3 particu-lates enhance the potential barrier of Ti ions from M/MO interface to O/MO interface,thereby the TiO2.growth rate decreases,which is also beneficial to improve the oxidation resistance.

关键词： Al2.3/TiAl matrix composite oxidation resistance high temperature

Relationship between the Corrosion and Cr-Ni Content of Stainless Steel in Borax Bath

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Journal of Wuhan university of technology({2. science) 2011年第6期26卷 1137-1139页

作者：王俊元 school of Mechanical engineering and Automation North University of China

The corrosion of stainless steel was experimentally investigated and analyzed to improve the service-life of the crucible and fixture clamps. Through the experiment, stainless steel was found to satisfy the crucible and fixture clamps materials. As the chromium element mass percentage of the stainless steel increased, the corrosion decreased rapidly at first and then slowly increased. With the corrosion time prolonging, the corrosion growth rate is generally a downward trend. With Chromium 2.%, the corrosive were the least. With Nickel element mass percentage increased, the corrosion increased rapidly at first and then decreased rapidly, flatten at the last. It was special that the corrosion had little relationship with the Chromium and Nickel mass percentage when the Nickel percentage is more than 35%. The most remarkable corrosion is corresponding with the Nickel element 12., the least corrosion with Nickel element 80%. So Nickel element 35% is the most optional.

关键词： corrosion chromium nickel stainless steel borax bath

Effect of Nd_2.e_(14)B/α-Fe Nanocomposite Permanent Magnets with a Combined Co and Nb Additions

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Journal of Wuhan university of technology({2. science) 2009年第5期24卷 725-727页

作者：马瑞 school of materials {2. and Metallurgy engineering Guizhou University

Influence of Co＋Nb on the Nd8Fe82.o3Nb1B6 nanocomposite magnets was investigated by adding Co element combined with Nb element. Results show that the high temperature stability of two phases is increased. Adding Co＋Nb could improve the glass forming ability of the alloy, reduce the size of grains, increase the exchange coupling ability of two phases, and obviously increase the magnetic properties of the alloy. The optimal magnetic properties are Br=1.14 T, Hcj=32. kA/m, （BH）max=109.3 kJ/m^3

关键词： nanocomposite permanent magnets glass forming ability exchange coupling ability magnetic properties

Wear characteristics of spheroidal graphite roll WC-8Co coating produced by electro-spark deposition

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Rare Metals 2010年第2期29卷 174-179页

作者： WANG Jiansheng, MENG Huimin, YU Hongying, FAN Zishuan, and SUN Dongbai school of materials {2. and engineering, university of {2. and technology Beijing, Beijing 100083, china school of materials {2. and engineering University of Science and Technology Beijing

Electro-spark deposition（ESD） was adopted for preparing high property coatings by depositing WC-8Co cemented carbide on an spheroidal graphite roll *** microstructure and properties of the coating were investigated by X-ray diffraction（XRD）, scanning electron microscopy（SEM） with energy dispersive X-ray（EDX） and ball-disc configuration wear *** results show that nanosized particles and amorphous structures prevail in the coating which is metallurgically bonded to the *** microstructures of the transition zone include columnar structure and equiaxed *** primary phases of the coating contain W2., W6C2.54, Fe3W3C, and *** results of abrasive test show that the coating has low friction coefficients（μaverage = 0.18） and the wear mechanisms are mainly abrasive wear, fatigue wear, and oxidation *** maximum microhardness value of the coating is about 17410 N/*** study reveals that the electro-spark deposition process has better coating quality and the coating has high wear resistance and hardness.

关键词： electro-spark deposition WC/Co coatings wear resistance microstructure