Structure and ordering of the 18-carat Al-Au-Cu β-phase

被引:25
作者
Cortie, MB [1 ]
Levey, FC [1 ]
机构
[1] MINTEK, ZA-2125 Randburg, South Africa
关键词
intermetallics; miscellaneous; crystal chemistry of intermetallics; crystallography; site occupancy;
D O I
10.1016/S0966-9795(00)00011-X
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Gold alloys with around 30 at% copper and 25 at% aluminium undergo a reversible displacive transformation with M-s and A(s) temperatures of about 30 and 75 degrees C respectively. However, the nature of the parent and product phases in this system has not previously been clear. It is confirmed here that the parent phase is a beta electron compound. If it is annealed and quenched, it has ordering intermediate between the A2 and B2 states, and in this case the displacive transformation between the parent phase and the low temperature (martensite) phase is poorly developed, and has some second order characteristics. Ageing of the parent phase causes it to take up L2(1)-type ordering after which the transformation becomes classically displacive and reversible, with many of the characteristics associated with the known shape memory systems. The site occupancies of the parent phase have been estimated. (C) 2000 Elsevier Science Ltd. All rights reserved.
引用
收藏
页码:793 / 804
页数:12
相关论文
共 37 条
[11]  
INDEN G, 1991, MAT SCI TECHNOLOGY, V5, P499
[12]  
ISOBE Y, 1991, Patent No. 2267237
[13]   Thermoelastic martensite and shape memory effect in ductile Cu-Al-Mn alloys [J].
Kainuma, R ;
Takahashi, S ;
Ishida, K .
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1996, 27 (08) :2187-2195
[14]   Ordering in the sublattices of Fe3Al during the phase transformation B2⇆D03 [J].
Kopecek, J ;
Kratochvíl, P ;
Rafaja, D ;
Plischke, D .
INTERMETALLICS, 1999, 7 (12) :1367-1372
[15]  
KRUMHANSL JA, 1995, J PHYSIQUE, V2, P3
[16]   THE AGING EFFECT ON CU-ZN-AL SHAPE MEMORY ALLOYS WITH LOW CONTENTS OF ALUMINUM [J].
LEU, SS ;
HU, CT .
METALLURGICAL TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE, 1991, 22 (01) :25-33
[17]  
LEVEY FC, 1998, P MICROSC SOC SO AFR, V28, P18
[18]  
LEVEY FC, 1999, IN PRESS P INT C SOL
[19]  
LEVEY FC, IN PRESS METALL MA A
[20]  
LEVEY FC, 1995, J PHSYIQUE, V8, P1087