A.T.Male
,
Y.W.Chen
,
P.J.Li
,
C.Pan
,
Y.M.Zhang
材料科学技术（英文）
Plasma-jet forming is a newly proposed flexible sheet metal forming process. A non-transferred arc plasma torch is used as a controllable heat source to produce internal stress in sheet metals, causing plastic deformation without the necessity of hard tooling. This method has potential for rapid prototyping of sheet metal parts by reducing development costs and lead times. A robotic system has been used to perform simple linear bends in several different alloys. In order to develop a controllable process and to improve the forming accuracy, the effects of various process parameters on the obtained shape changes and ton the resulting structure and properties have been studied. The overall goal is to understand the roles of the forming parameters and their inter-relationship in optimizing the forming procedure-a high forming speed without damage to the material structure or properties.
关键词:
NING Yuantao LI Yongnian Kunming Institute of Precious Metals
,
Kunmmg
,
China Professor
,
Kunming Institute of Precious Metals
,
Kunming
,
Yunnan
,
China
金属学报(英文版)
The internal oxidation behavior of Pd-40Ag-1M(M=Zr,Y)alloy wires has been studied in air at 800—1200℃.The relationship between the internal oxidation depth ξ and the reaction time t can be expressed as ξ= Kt~n,where n=0.5—0.75.The higher the temperature,the larger the value of n is.The active elements Zr and Y show different internal oxidation characters.For the alloys eontaining Zr,the oxidation rate along the grain boundaries is about twice as high as that in grains,and“lateral oxidation”exists along the grain boundaries.For the alloys containing Y,the oxidation rates in grains and along the grain boundaries are roughly the same,and there is no“lateral oxidation”along the grain bounda- ries.The activation energies of both alloys are in the range of 120—150kJ/mol.Some prop- erties for oxidized alloys were studied.The mechanisms of the internal oxidation were dis- cussed.
关键词:
Pd-40Ag alloy
,
null
,
null
,
null
,
null
王龙章
,
黄克雄
,
骆如铁
,
姚渝
,
叶大陆
,
陈新民
金属学报
本文讨论了双金属共存体系M_1-M_2-x-y,当两种金属的化合物相互作用生成多金属化合物时,优势区相图的绘制原理、方法及计算机程序。通过绘制Zn-Fe-SO系的优势区相图,分析了ZnO·Fe_2O_3的生成及稳定条件,并说明了其在硫化锌矿焙烧中的指导作用。
关键词:
M_1-M_2-x-y体系
,
predominance diagram
,
roasting
,
zinc sulfide ore
Physical Review B
The magnetic properties of 13-atom M clusters (M=Y, Zr, Nb, Mo, and Tc) with three possible high-symmetry geometries have been studied using the discrete-variational local-spin-density-functional method. While the ground states of most transition-metal 13-atom clusters correspond to the icosahedral structure, we found that the cuboctahedral structure is more energetically stable than the icosahedral one for Mo-13 and Tc-13 clusters. The ground states of all the clusters are shown to be magnetic, but their magnetic moments are not striking.
关键词:
rhodium clusters;metal-clusters;molecules;symmetry;states
王塞北
,
邱红莲
,
张吉明
,
胡洁琼
,
王松
,
陈永泰
,
悟有才
,
魏宽
,
谢明
贵金属
采用基于密度泛函理论的第一性原理赝势平面波方法，计算了Au-Pd-M(M=Mo, Y, Zr)合金中可能存在的各种合金相的结合能与生成焓，讨论了合金相的稳定性。结果表明，Au-Pd-M固溶体中，添加质量比为1%的Mo元素形成的固溶体，其结合能与生成焓是Au-Pd-M(M=Mo, Y, Zr)系固溶体中最低的。Au-Pd-Y系合金中最为稳定的中间相是YPd3。Au-Pd-Zr系合金中，形成PdZr2的反应最容易发生，生成的合金相惁是最为稳定的，其次是AuZr3。
关键词:
金属材料
,
第一性原理
,
Au-Pd-M(M=Mo, Y, Zr)
,
固溶体
,
中间相
宁远涛
,
李永年
金属学报
在800—1200℃大气气氛中研究了直径0.1-2.0mmPd-40Ag-1Zr和Pd-40Ag-1Y合金丝的内氧化行为及其对性能的影响、内氧化深度ξ与反应时间t的关系可以表示为ξ=Kt~n,其中反应指数n=0.5-0.75。温度越高,n值越大,对内氧化抛物线规律偏离越大,活性元素Zr和Y有不同内氧化特性:含Zr合金晶界氧化速度比晶内氧化约快一倍,且沿晶界存在“侧氧化”;含Y合金晶界与晶内氧化速度相差不大,不存在沿晶界的“侧氧化”。两种合金的内氧化激活能在120—150kJ/mol范围内。讨论了两种合金的内氧化机制。
关键词:
Pd-40Ag合金
,
Y
,
Zr
,
internal oxidation
杨书廷
,
张焰峰
,
吕庆章
,
贾俊华
,
丁立
,
张明春
应用化学
doi:10.3969/j.issn.1000-0518.2000.05.010
以Li2CO3、Mn(NO3)2和M(NO3)3(M=La,Nd,Y)为原材料,用溶胶-凝胶方法和微波加热技术合成了纳米级尖晶石LiMxMn2O4(M=La,Nd,Y)材料,XRD实验表明, 微波合成的材料相纯度较高,充放电实验表明,在LiMn2O4中掺杂摩尔比为0.006的La 、Nd和Y可以提高其电化学比容量和充放电循环性能.
关键词:
LiMn2O4
,
掺杂
,
稀土
,
微波化学
Journal of Materials Research
The morphology of the dark and bright regions observed by transmission electron microscopy for the Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass strongly depends on the ion beam parameters used for ion milling. This indicates that the ion beam could introduce surface fluctuation to metallic glasses during ion milling.
关键词:
room-temperature
Transactions of Nonferrous Metals Society of China
The influence of Zr and Y on the cast microstructure of a nickel-based superalloy was investigated by optical microscopy (OM), scanning electron microscopy(SEM), electron probe micro-analysis (EPMA) and X-ray diffraction (XRD). The gamma+gamma' eutectic volume in the superalloy rises notably with the increase of Zr or Y content. Meanwhile, the morphologies of primary MC carbides change from needle and platelet-like to blocky shape with increasing Zr and Y doped. The XRD results show that the primary MC carbide lattice constant increases with Zr and Y additions, and EPMA investigation shows that the platelet-like MC carbides contain primarily Nb and C, while those carbides in blocky shape have 39.2% Zr and 39.6% Nb in average,. These influences on the cast microstructure can be attributed to the atomic size effects of Zr and Y.
关键词:
yttrium;zirconium;carbides;nickel based superalloys;microstructure;solidification;carbide morphology;mechanical-properties;boron;ni3al;yttrium;sulfur
