摘要
对[110]和[112]取向的单晶Sn试样在不同温度和不同应变速率下进行了拉伸实验.结果表明,两种取向的Sn单晶体对应变速率都极为敏感,[110]取向晶体的应变速率敏感指数m为0.133,高于[112]取向的0.108,表现出较高的塑性.单晶Sn在变形过程中表现山很强的加工硬化,[110]取向试样的加工硬化指数n约为0.54,高于[112]取向的0.46.通过电镜观察得到,[110]取向试样的变形以多系滑移方式进行,[112]取向试样是以交滑移和孪晶方式共同进行变形;[110]取向晶体首先开动的滑移系是{010}<100>,开动这个滑移系的临界分解切应力(CRSS)为3.1 MPa.两种取向的单晶体变形的激活能Q在35—52 kJ/mol之间,根据激活能和滑移形貌的观察.得出变形过程是由交滑移机制控制的结论.
Deformation behaviors of [110] and [112] oriented Sn single crystals were investigated under different temperatures and strain rates. It is shown that there are some differences between [110] and [112] orientations. [110] oriented sample has the higher strain rate sensitivity exponent m≈0.133, strain hardening exponent n≈0.54, activation energy Q≈35 kJ/mol and deforms through multiple slip. While [112] oriented sample has the lower strain rate sensitivity exponent m≈0.108, lower strain hardening exponent n≈0.46, activation energy Q≈52 kJ/mol and deforms through cross-slip and twins together. The first activated slip system is {010}〈100〉 in [110] orientation. The critical resolved shear stress （CRSS） is 3.1 MPa which is depended on temperature. Deformation process is controlled by the cross-slip according to the activation energy and slip observation.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2008年第12期1409-1414,共6页
Acta Metallurgica Sinica
基金
国家重点基础研究发展计划资助项目2004CB619306~~
关键词
单晶体Sn
应变速率敏感指数
激活能
加工硬化指数
交滑移
滑移系
临界分解切应力(CRSS)
Sn single crystal, strain rate sensitivity exponent, activation energy, strain hardening exponent, cross slip, slip system, critical-resolved shear stress （CRSS）
