机械合金化Cu-Sn二元形状记忆非晶态合金的XAFS研究  

XAFS study on local structures of mechanically alloyed Cu-Sn amorphous shape memory alloys

作　　者：贺博[1] 熊永红[2] 熊曹水[2] 何洪涛[1] 韦世强[1] 

机构地区：[1]中国科学技术大学国家同步辐射实验室,合肥230029 [2]华中理工大学物理系,武汉430074

出　　处：《核技术》2003年第8期569-572,共4页Nuclear Techniques

基　　金：中国科学技术大学一流大学建设重点项目

摘　　要：利用X射线吸收精细结构(XAFS)方法研究了机械合金化(Mechanical alloying,MA)方法制备的Cu-Sn二元金属合金在球磨过程中的结构变化。研究结果定量地表明,随着球磨时间的增加,Cu-Cu的键长逐渐变大,Cu第一近邻Cu-Cu配位数减小;Cu-Sn配位数逐渐增大,Cu与Sn的合金化程度和均匀性也随之增加。球磨4h后,Cu-Cu的配位数由Cu粉的12降低为7.4,键长由2.55 增加到2.63 ;球磨12h后,Cu-Cu的配位数降低到6.4,Cu-Sn的配位数由0变到5.1,键长约为2.8抛笥遥磺蚰?2h的结果与球磨12h的结果相近,说明Cu与Sn的互扩散过程基本达到平衡,形成组成近似于Cu6Sn5的非晶合金。The local structures of mechanically alloyed Cu-Sn mixtures have been investigated by X-ray absorption fine structure (XAFS) technique. The result indicates that the bond length of the Cu-Cu first shell slightly increases and the coordination number of the Cu-Sn first shell largely increases with the milling times for the Cu-Sn alloys. This means that the inter-diffusion between Cu and Sn grains, driven by mechanical alloying, results in forming Cu-Sn alloy. After milling 4h, the coordination number and the bond length of the Cu-Cu first shell change from 12 to 7.4 and from 2.55 ?to 2.60 ?for the Cu-Sn alloys, respectively. After 12h milling, the coordination number of the Cu-Cu first shell decreases to 6.4 while that of the Cu-Sn first shell increases to 5.1 and its bond length is about 2.80 for the Cu-Sn alloy. Furthermore, the XAFS result for the Cu-Sn alloy milled for 72 h is similar to that for 12 h. This implies that the inter-diffusion between Cu and Sn grains has nearly reached the equilibrium and an amorphous Cu-Sn alloy of Cu6Sn5-like is formed.

关 键 词：X射线吸收精细结构 机械合金化 Cu-Sn合金 

分 类 号：O722.8[理学—晶体学]