Thermal cycling effect in Cu-11.9Al-2.5Mn shape memory alloy with high MSUB>s temperature

来源期刊：中国有色金属学报(英文版)2002年第4期

论文作者：曹玲飞 汪明朴 李周 徐贲 苏玉长

文章页码：716 - 719

Key words：shape memory alloy；Cu-Al-Mn alloy；martensite；thermal cycling；thermostability

Abstract: The effects of thermal cycling on marten site transformation in Cu-11.9Al-2.5Mn(mass fraction, %) shape memory alloy(SMA) with high M_s temperature were studied by means of electrical tension vs temperature (U—T) measurement, optical microscopy observation and X-ray diffractometry. It shows that with increasing thermal cycles, the transformation temperatures decreased, which are accompanied by changes of martensite structure such as the decline of NNN ordering degree and monoclinic angle β→90°. Compared with traditional Cu-base SMA, the alloy has rather high thermostability and can work at 2 00～300℃. Its excellent thermostability comes from two factors: 1) its β₁ parent structure is stable and difficult to decompose at work temperature; 2) its martensite structure is close to N18R(β=89.6°), which restrains the process of M18R→N18R and the tendency of martensite stabilization and decomposition.