YANG Yuanzheng MA Xueming DONG Yuanda Institute of Solid State Physics
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Academia sinica
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Hefei
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China Professor.Institute of Solid State Physics Academic Sinica
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Hefei 230031
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China
金属学报(英文版)
Mechanical alloying was employed to produce super—saturated solution of Fe_1-xCu_x ,which is virtually immiscible under an equilibrium condition at ambient temperature.XRD results show that the solutions formed in the concentration ranges of x≤O.15 and x≥0.40 are of bee structure of x-Fe and fee structure of Cu,respectively.For the region in between (0.15bee plus fee phases.DSC traces indicate that there exist two broad exothermal peaks for all samples,the first peak responds to the releasing of stored strain and the second to the decomposition of solid solutions.
关键词:
mechanical alloying
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null
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null
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null
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null
王瑞
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周灵平
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汪明朴
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朱家俊
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李德意
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李绍禄
材料科学与工程学报
采用双靶磁控溅射共沉积方法制备Cu-W薄膜,其微观结构及形貌通过XRD、TEM和SEM方法测试,结果表明,Cu-W薄膜是由Cu固溶于W或W固溶于Cu的亚稳态固溶体组成,且随着W含量的增加,Cu-W薄膜依次形成面心立方fee结构的Cu基亚稳固溶体、fee和bee结构固溶体的双相区以及体心立方bee结构的W基亚稳固溶体,晶粒尺寸随溶质原子含量的增加而减小.这些亚稳固溶体的形成是由于溅射出的原子动能足以克服Cu、W固溶所需的混合热.以及溅射过程中粒子的纳米化和成膜过程中引入的大量缺陷造成的.
关键词:
低维金属材料
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铜钨薄膜
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磁控溅射
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亚稳固溶体
Journal of Materials Science
Solid state amorphizations in mechanically deformed Ni/Ti multilayer composites have been investigated by differential scanning calorimetry and X-ray diffraction. The growth of amorphous alloy in our Ni/Ti composites was facilitated by the large number of grain boundaries and relatively large degree of disorder induced in the metal layers by the cold rolling. The formation of different products of solid-state reaction in the Ni/Ti composites has bee,n elucidated in terms of magnetic and enthalpy analysis. It is thought that the solid state amorphization occurs first during heating, followed by the formation of intermetallic compounds through direct solid-state reaction of elemental nickel and titanium and by the crystallization of the amorphous alloy already formed by the solid state amorphization reaction. The values of the activation energy for interdiffusion and interdiffusion coefficient for the formation of amorphous alloy in the Ni/Ti composites have also been calculated.
关键词:
diffusion couples;interdiffusion reactions;elemental composites;thin-films;ni/zr;ni;planar;binary;growth;alloys
Acta Physica Sinica
In this work, the microscopic defects in Ti-Mo alloy hydrides were studied by using small-angle X-ray scattering (SAXS) technique. The results show that the SAXS intensity measured for hydride of 5at% Mo alloy was lower than that of other hydrides in the high scattering angle range. The crystal grains and its internal sub-structures in the hydrides are the scatterers which cause SAXS. The sub-structures are induced by the large number of dislocations in the hydrides produced during hydrogenation. The crystal structure of Mo 5at% alloy is mainly hcp, but that of the other alloys is bcc. The hydrides of all these alloys, however, have a fee crystal structure. Therefore, it is indicated that the Ti-Mo alloys with hcp and bee crystal structures form the same hydride structure,but induce different types of dislocation defects during hydrogenation.
关键词:
Ti-Mo alloy hydride;small-angle X-ray scattering;microscopic defects;single-crystal pd;powder diffraction;sans measurements;dislocations;deuteride;neutron;system
WANG Weiguo ZHANG Yijin HUANG Jianchao Central South University of Technology
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Changsha
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China WANG Weiguo Lecturer
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Department of Materials Science and Engineering
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Central South University of Technology
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Changsha
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China
金属学报(英文版)
The microstrueture in shape memory alloy Cu—14Al—4Ni aged for two years at room temper- ature has been studied,and the substructure slow change has been observed.The domains of highly ordered phase and the transition regions appear at grain boundaries,the twin bounda- ries damage.Furthermore,the microstructure also gives the appearance and growth of antiphase domains like rectangular network.The long period antiphuse boundary structures and the antiphase domains have bee.observed first at the single diffracted vector .The con- centration gradient of solute atom Al has heen found from the matrixes to the grain bounda- ries,the matrixe is poor in Al and the grain boundaries are rich in Al.
关键词:
shape memory alloy
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null
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null
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null
程兴旺
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孙坤
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王富耻
稀有金属材料与工程
采用分离式Hopkinson压杆技术对Ti-15Mo-3Al-2.7Nb-0.2Si钛合金的帽形试样进行了强迫剪切试验,通过扫描电镜(SEM)及透射电镜(TEM)研究了Ti-15Mo-3Al-2.7Nb-0.2Si钛合金在动态加载下绝热剪切带的微观结构演化.结果表明:Ti-15Mo-3Al-2.7Nb-0.2Si钛合金由于其组织以bee晶格的a相为主,具有较好的变形能力,因此其绝热剪切带的形成是位错运动的结果;剪切带的微观结构演化过程为:晶粒在外加切应力作用下拉长变形一拉长晶粒的破碎-形成呈一定方向排列的细小等轴晶:带内形成的细小等轴晶尺寸为O.2～0.4ìm.
关键词:
钛合金
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绝热剪切带
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微观分析
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金属材料
马坪
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吴二冬
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李武会
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孙凯
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陈东风
金属学报
doi:10.3724/SP.J.1037.2013.00637
采用XRD和SEM分析了Ti07Zr0.3(Cr1-xV)2(X=0.1,0.2,0.3,0.4)合金的相组成、晶体结构和元素成分;采用Sieverts装置、差热和热重分析仪(DTA-TG)测量了合金的活化性能、吸放氢P-C-T曲线、热力学参数及高温放氢特征.结果表明,合金为多相组织,存在C36(P63/mmc)和C15(Fd3m)2种Laves相和几种晶格常数近似的钒基bee固溶体相.当V含量较低时,合金主要由C36型Laves相和少量bcc固溶体相组成.随着V含量增加,C36型转变为C15型Laves相,其中第3种(C层)堆垛存在几率增加,而且合金中bcc固溶体相含量增加.合金在2MPa氢压和常温下能迅速活化;表面氧化后,x=0.1和0.2合金仍表现出优异的活化性能.随着V含量增加,合金的贮氢量增加、平台压力减小.合金氢化的相对偏摩尔焓变(△H)和熵变(△S)的变化范围为-7～-28 kJ/mol和-35～-95 J/(mol·K).DTA-TG分析表明,合金氢化物分解主要出现在500～600K温度区间,并呈现对应不同类型氢化物的2个分解温度,加热到800 K时合金中稳定的氢化物完全分解.
关键词:
贮氢
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Laves相
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固溶体相
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P-C-T曲线
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热力学
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热重分析
