H.B. Ji
,
L.F. Xia
,
X.X. Ma
,
Y. Sun and M.R. Sun School of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin 150001
,
China
金属学报(英文版)
The surface properties Of Ti-6Al-4V alloy coated with titanium nitride, TIN + TiC + Ti(C,N)/DLC, TIN/DLC, and TI C/DLC films by plasma-based ion implantation (PBII) with nitrogen, PBH with nitrogen then acetylene, PBII with nitrogen then glow discharge deposition with acetylene plus hydrogen, and PBH with acetylene then glow discharge deposition with acetylene plus hydrogen, respectively, are compared (DLC: diamond like carbon). The corresponding films are found getting dimmer: light gold or gold, smoky color (uneven), light red in black (uneven), and graphite black. and the corresponding film resistivities are about: (1. 0--3. 3) x 10~7, (0. 05- 2. 00) x 10~11 ) (0.016-2.400)× 10~11, and (0.45-1.01)x 10~11 Ω/cm, respectively. Antioxidation ability of the titanium nitride film is poor while existence of carbon (or carbide) improves the antioxidation ability of the films. Having underpone excellent intermediate transitional region of nitrogen and carbon implantation, the top DLC layer of the TIN+TIC+Ti(C,N)/DLC multilayer formed after the carbon implantation has the best adhesion with the substrate among all the multilayers presented. Although microhardness of the samples increases in the order of coatings of titanium nitride, TIN/DLC, TiN+TiC+Ti(C,N)/DLC, and TiC/DLC, the TIN/DLC and TiC/DLC multilayers have greater brittleness compared with other films presented.
关键词:
Ti-6Al-4V
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null
,
null
,
null
,
null
Z.J. Zhan
,
X.X. Ma
,
Y. Sun and L.F. Xia School of Materials Science and Engineering
,
Harbin Institute of Technology
,
Harbin 150001
,
China
金属学报(英文版)
Aluminum alloy 2024 has been implanted with nitrogen ions at various doses by plasma based ion implantation (PBII). The introduction of energetic ions caused structural change within the near surface region of the solid. The samples have been characterized by X ray Photoelectron Spectroscopy at various depths. The chemical states of Al and N were identified by deconvolution of the recorded XPS spectra. After plasma based ion implanted nitrogen into aluminum, not only the AlN precipitates but also supersaturated solution of nitrogen formed. The presence of aluminum in different chemical states corresponding to Al, AlN and Al 2O 3. The majority of nitrogen participates in the form of the supersaturated solution. With the increase of nitrogen dose, the amount of AlN precipitates increased.
关键词:
plasma based ion implantation
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null
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null
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null
Lizhi CHENG
,
Wei FENG
,
Xinquan DONG
,
Kuichang BAI and Kaiyuan HE (Dept. of Materials Science and Engineering
,
Northeastern University Shenyang 110006
,
China)
材料科学技术（英文）
The formation of nonequilibrium phase by mechanical alloying (MA) of Fe and B powders in a high energy vibration ball mill has been made for Fe100-xBx system with x=15. 30, 35, 45,55 and 70. By using the X-ray diffraction, magnetic measurement and M6ssbauer spectrummethods, it was revealed that the structure of the MA product varies with milling time and B contents.
关键词:
International Journal of Hydrogen Energy
La(2-x)Ti(x)MgNi(9) (x = 0.2, 0.3) alloys have been prepared by magnetic levitation melting under an Argon atmosphere, and the as-cast alloys were annealed at 800 degrees C, 900 degrees C for 10 h under vacuum. The effects of annealing on the hydrogen storage properties of the alloys were investigated systematically by XRD, PCT and electrochemical measurements. For the La(2-x)Ti(x)MgNi(9) (x = 0.2, 0.3) alloys, LaNi(5), LaMg(2)Ni(9) and LaNi(3) are the main phases and a Ti(2)Ni phase appears at 900 degrees C. The effective hydrogen storage capacity increases from 1.10, 1.10 wt.% (as-cast) to 1.22, 1.16 wt.% (annealed 800 degrees C) and 1.31, 1.27 wt.% (annealed 900 degrees C), respectively. The annealing not only improves the hydrogen absorption/desorption kinetics but also increases the maximum discharge capacity and enhances the cycling stability. The La(1.8)Ti(0.2)MgNi(9) alloy annealed at 900 degrees C exhibits good electrochemical properties, and the discharge capacities decrease from 366.1 mA h/g to 219.6 mA h/g after 177 charge-discharge cycles. (C) 2010 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.
关键词:
Hydrogen storage alloy;Annealing;Hydrogen storage property;electrochemical properties;electrode alloys;absorption;system
材料科学技术（英文）
The structure, specific heat, magnetic and electrical properties of MnTe(1-x)Sb(x) (x=0, 0.1, 0.15, 0.2 and 0.25) alloys have been investigated. The MnTe(1-x)Sb(x) alloys crystallize in a hexagonal NiAs-type structure, and the impurity of MnSb phase appears when x >= 0.15. The MnTe(0.9)Sb(0.1) compound exhibits ferrimagnetic behavior with hysteresis loops even at 350 K, showing that the magnetic properties of MnTe compound are very sensitive to little compositional change. The ferromagnetism in the MnTe(1-x)Sb(x) alloys with higher Sb contents may be attributed to the impurity of MnSb phase. Energy dispersive X-ray spectroscopy analysis on the MnTe(0.9)Sb(0.1) compound indicates that Sb is very difficult to dope into the lattice of MnTe. So the anomaly of resistivity at 300 K of MnTe(0.9)Sb(0.1) and the peak of specific heat around 304 K of all the alloys are thought to be related with the antiferromagnetic interactions of MnTe-based lattice.
关键词:
Electronic transport property;Hysteresis loop;Specific heat;manganese telluride;semiconductors;ferromagnetism;scattering;exchange
Powder Diffraction
The structure transitions and phase relationships of DyFe(3-x)Al(x) compounds have been investigated by X-ray powder diffraction. Our XRD results show that each of the compounds with x <= 0.45 crystallizes in the rhombohedral PuNi(3)-type structure with space group R (3) over barm and Z=9; for the 0.8 <= x<1.0 compounds, each has a hexagonal structure of the CeNi(3) type with space group P6(3)/mmc and Z=6; and each of the samples with 0.45<x<0.8 is a two-phase mixture of the PuNi(3)- and CeNi(3)-type structures. The calculated XRD intensities of the DyFe(3-x)Al(x) compounds with x=0.2, 0.33, 0.4, and 0.45 indicate that Dy occupies the 3a and 6c sites, Fe and Al distribute randomly on the 18h site, and the 3b and 6c sites are exclusively occupied by Fe, which agrees well with those of our experimental XRD patterns. The XRD intensities of the DyFe(3-x)Al(x) compounds with x=0.8 and 1.0 have also been calculated and found to agree with the experimental results with Dy on the 2c and 4f sites, Fe and Al at the 12k site, and Fe at the 2a, 2b, and 2d sites. In the two-phase region with x=0.45-0.8, the values of unit-cell parameters and phase compositions are linearly dependent on the value of x, indicating that the two phases are constituted by the same composition x with different stacking arrangements. This abnormal two-phase equilibrium is further confirmed by the structural analysis of the DyFe(2.33)Al(0.67) (or x=0.67) sample. The samples with x=1.1 and 1.2 were also analyzed, and each found to be a mixture of more than two phases. (C) 2010 International Centre for Diffraction Data. [DOI: 10.1154/1.3507088]
关键词:
X-ray powder diffraction;DyFe(3-x)Al(x) system;structure change;anomalous phase composition;magnetic-properties;intermetallic compounds;al substitution;rare-earth;fe;dy6fe23;refinement;aluminum;dy2fe17;co
Journal of Magnetism and Magnetic Materials
The ingot of Fe-(18-x) at% Ga-x at% Al (3 <= x <= 13.5) alloys was prepared from high purity elements using a high vacuum arc melting system. The X-ray diffraction patterns indicated that the alloys were disordered bcc A2 structure. The magnetostriction of the alloys was measured and the effect of partial substitution of Ga with Al on the magnetostriction of the alloys was investigated. Fe-9 at% Ga-9 at% Al alloy, the optimizing magnetostrictive alloy was found in Fe-(18-x) at% Ga-x at% Al (3 <= x <= 13.5) alloys. The saturated magnetostriction of the directional solidification Fe-9 at% Ga-9 at% Al rod is up to 135 ppm for 0 MPa and 221 ppm for 53 MPa. It was found that the alloy has the high linearity of the magnetostriction curve, the low hysteresis and saturated magnetic field, which suggests the directional solidification Fe-9 at% Ga-9 at% Al alloy is a potential candidate for magnetostrictive actuator and transducer applications. (C) 2010 Elsevier B.V. All rights reserved.
关键词:
Fe-Ga-Al alloy;Magnetostriction;Microstructure;fe-rich portion;phase-equilibria;system;elasticity;stability
Physical Review B
NdCo(12-x)V(x) (2.2 <= x <= 2.6) crystallizes in the ThMn(12)-type structure and exhibits an unusual jump in the magnetization at a critical field B(C) that decreases with increasing V content. It was intriguing that the magnetization of the bulk samples below B(C) was very close to that of YCo(12-x)V(x) with the same V content. To investigate the nature of the magnetic order in these materials we have carried out powder neutron diffraction measurements as a function of temperature and magnetic field on the NdCo(9.5)V(2.5) composition. In zero field we find that both the Nd and Co ions have substantial ordered moments (similar to 2.9 and 0.4 mu(B), respectively) at low temperature (4 K), with the moments coupled ferromagnetically (T(C)=180 K) and aligned along the c axis. On a loose powder an applied field of 4 to 7 T rotates the particles so the c axis aligns with the field, indicating a strong uniaxial anisotropy that renders the system Ising-like. However, we find the same in-field magnetic structure and essentially the same values for the saturated magnetic moments as those in zero field. Magnetization data on magnetically prealigned samples reveal that for fields applied parallel to the (easy) c axis the magnetization saturates below 0.5 T at a magnitude that is in very good agreement with the moments determined from neutron diffraction. For fields applied perpendicular to the c axis, on the other hand, the magnetization data show a two-plateau behavior, explaining the original magnetization data on randomly oriented powders. The strong dependence of the magnetization on the direction of the applied magnetic fields indicates an occurrence of the first-order magnetization process due to the competing magnetocrystalline anisotropies of the Nd and the Co sublattices and of the higher-order terms of the anisotropy energy.
关键词:
rare-earth;intermetallic compounds;thmn12 structure;transition;anisotropy;crystal;fe;substitution;ndco9.5v2.5;compound
郭可信
金属学报
<正> X射线在金属学及金属物理这一学科中的应用日益广泛,它已经是从事金属研究的科学工作者所不可缺少的工具.同时,金属X射线学也已经成为一门新的边缘学科分支,是金属学及金属物理专业的必修课程.但是,在这方面,迄今为止尚无一本我国科学工作者编写的教材或参考书,仅有的几种译本亦都有内容贫乏与过时的缺点.因此,许顺生同志著的“金属X射线学”的出版是值得欢迎的.本书的内容范围相当广泛,并且是此较全面的.全书共26章,可以粗略地分五个部分:第一部分(1—5章):基本理论,包括X射线物理及晶体学基础,X射线衍射的几何及强度理论;第二部分(6—10章):各种实验方法,如劳厄、周转晶体、粉末及小角度散射法;第三部分(11—15章):X射线晶体学的一
关键词:
朱桂兰
,
何崇智
钢铁研究学报
简要介绍了德国布鲁克AXS公司新产品D8系列X射线衍射仪的特点、实验方法的分析软件及其应用.该系列仪器具有超前的技术,卓越的品质,可为物质微观结构的分析和前沿研究工作提供有效的解决方案.
关键词:
X射线衍射仪
