Order-disorder Transformation for TiAl with L1_0 Structure at Stoichiometrical Composition

作     者：Timothé e Nsongo, Xiaodong Ni,Guoliang Chen,Keh-Minn Chan 1) State Key Laboratory for Advanced Metals and Materials, University of Science and Technology Beijing, Beijing 100083, China 2) Faculty of Science (Physics Department, P.O. Box 69 Brazzaville, 

作者机构：北京科技大学 新金属材料国家重点实验室 北京 100083 West-Virginia University 美国 

出 版 物：《Rare Metals》 (稀有金属（英文版）)

年 卷 期：2001年第20卷第3期

页      面：147-151页

核心收录：

学科分类：0806[工学-冶金工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 0703[理学-化学] 0702[理学-物理学] 

基　　金：This work was financially supported by the National Natural Science Foundation of China under Contract No.59895151-01 

主　　题：order-disorder transformation TiAl long-range order intermetallic 

摘      要：The embedded atom method (EAM) was used to study the order-disorder transformation in gamma -TiAl alloy with L1(0). structure at stoichiometrical composition, and the effect of lattice constants was also investigated. It was found that the gamma -TiAl alloy at stoichiometrical composition exhibits a second-order transition, and the relations between lattice constants a, c and the long-range order sigma are not linear. The lattice constant a decreases whereas c increases with the increase of the long-range order parameter. In this case the ordering induces the transformation from cubic to tetragonal. The change of the lattice constant during the ordering processes can be interpreted in terms of bond length.