材料期刊网

STRUCTURE AND PROPERTIES OF RE-Ni-B-Al_2O_3 COATING MATERIAL

Z.C Guo , X.W Yang , H.K Lin , Z.Y Wang and M. Wang(Department of Metallurgy , Kunming University of Science and Technology Kunming 650093 , China)

金属学报(英文版)

The effects of heat treatment temperature on the hardness, wear resistance and structure of a coating material consisting of Ni-0.45wt% RE4.8wt% B-6.2wt% Al2O3 have been discussed. The results showed that the hachess and wear resistance of the composite material reach the optimal values when heating temperature rises to 350℃ and 500℃ respectivelg. X-ray diffraction and scanning electron microscopy indicate that the composite material is amorphous in the as-coating state. The crystallized temperature of Ni-B alloy is increased when RE and Al2O3 particles are inserted. The hardness and wear resistance of the composite are raised obviously with addition of RE and Al2O3 particles.

关键词: RE-Ni-B-Al_2O_3 composite material , null , null

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

Ion sputter erosion in metallic glass-A response to "Comment on: Homogeneity of Zr(64.13)Cu(15.75)Ni(10.12)Al(10) bulk metallic glass" by L-Y. Chen, Y-W. Zeng, Q-P. Cao, B-J. Park, Y-M. Chen, K. Hono, U. Vainio, Z-L. Zhang, U. Kaiser, X-D. Wang, and J-Z Jiang J. Mater. Res. 24, 3116 (2009)

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

Brief Outline of the Metallurgy Department of Kunming Institute of Technology

LIU Chunpeng Kunming Institute of Technology , Kunming 650093 , China.

材料科学技术（英文）

关键词:

Department of Metallurgy and Materials Engineering of Chongqing University

YAN Guangting Chongqing University , Sichuan , China.

材料科学技术（英文）

关键词:

Microstructure and Tensile Properties of ZK60 Alloy Fabricated by Simplified Rapid Solidification Powder Metallurgy (S-RS P/M) Process

Zhenya Zhang

材料科学技术（英文）

This study investigated the microstructures and mechanical properties of ZK60 alloy prepared by a simplified rapid solidification powder metallurgy (RS P/M) processing system (S-RS P/M), which consists of warm press in dry air and hot extrusion. Microstructure characterizations showed that S-RS P/M alloy consisted of magnesium matrix and oxide stringers of ~1 μm in width. TEM (transmission electron microscopy) observations illustrated nano-size magnesia particles (10{30 nm) constituted oxide stringer in detail. Due to a relatively higher volume of nano-size magnesia particle produced during S-RS P/M process, 0.2% yield strength of S-RS P/M ZK60 alloy was found to be as high as 382 MPa, which is 10% higher than that of RS P/M alloy. The improvement in mechanical properties is mainly attributed to the combination effects of Orowan mechanism and coe±cient of thermal expansion (CTE) mismatch because of the approximately same average grain size.

关键词: Microstructure

纵向涡强化换热的M-Z干涉流动显示技术

刘永 , 宋耀祖

工程热物理学报

本文采用M-Z干涉测量的方法,研究了半三角形翼片纵向涡发生器强化换热方案对矩形通道内气体流动换热的影响,获得了安装纵向涡发生器前后对流换热温度场的M-Z干涉图像.通过对实验获得的干涉图像进行分析处理,表明安装纵向涡发生器后,通道内入口段流动的热边界层明显变薄,反映了纵向涡对流动换热的强化作用,验证了将M-Z干涉测量方法应用于纵向涡强化换热研究的可行性.

关键词: 纵向涡 , 强化换热 , M-Z干涉 , 热边界层

集成光学M-Z调制器的行波电极电场的有限元分析

刘威 , 唐多强 , 胡鸿璋

量子电子学报 doi:10.3969/j.issn.1007-5461.2001.02.009

报道了一种运用MATLAB语言对集成光学M-Z调制器行波电极的电场进行有限元分析的方法，得到了令人满意的计算结果，程序的运算时间缩短到原来的1/12.

关键词: 集成光学M-Z调制器 , 有限元法

敏化处理对Z3CN20-09M不锈钢高温水应力腐蚀的影响

陆永浩 , 陈子瑞 , 朱晓锋

材料科学与工艺

为了研究敏化处理对Z3CN20-09M不锈钢高温水应力腐蚀行为的影响，使用敏化处理的Z3CN20-09M不锈钢制成U弯试样，并置于250、290及320℃的高温水中进行应力腐蚀开裂实验，采用扫描电镜观察了高温水实验后试样的氧化膜厚度以及应力腐蚀裂纹的萌生及扩展行为。结果表明：敏化处理增加了氧化膜的厚度，降低了耐蚀能力，使SCC敏感性增大；温度较高时，敏化处理的影响较大；铁素体相容易被侵蚀，大多数点蚀坑产生于铁素体中；SCC裂纹优先在点蚀坑底部和奥氏体/铁素体相界位置处形成；相界面对SCC裂纹的影响取决于SCC裂纹相对于相界面的取向，SCC裂纹扩展方向平行于相界面时裂纹易沿着相界扩展，SCC裂纹扩展垂直于相界面方向时相界面对裂纹扩展起阻碍作用。

关键词: Z3CN20-09M , 敏化处理 , SCC裂纹 , 萌生和扩展 , 相界面

INTERNAL OXIDATION BEHAVIOR OF Pd-40Ag-1M(M=Zr,Y)ALLOYS

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