【摘要】 用扫描电镜 (SEM )对Zn Al合金超塑变形时的晶界 (或相界 )滑移特性进行了研究。结果表明 ,Zn Al合金的超塑变形机制是晶界 (或相界 )滑移 ,且α/β相界面滑移容易进行并可实现长程滑移 ,同时合金试样的表面特性对相界滑移有很大的影响。表面镀层对Zn 5Al合金超塑变形中的相界滑移有阻碍作用 ,而当试样在电场中进行超塑变形时 ,由于表面感应电荷的作用 ,导致试样表面产生大量的空洞 ,提高了超塑变形抗力 ,使应变速率和伸长率降低 ,表现为一种负的电塑性效应。更多还原

【Abstract】 The behavior of grain boundary (or phase boundary)sliding in super plastic deformation(SPD)of Zn Al alloy was studied with scanning electron microscope(SEM).The results show that the super plastic deformation mechanism of Zn Al alloy is grain boundary (or phase boundary)sliding,and α/β interfaces slide easily and can realize long distance sliding,furthermore,the surface effect has strong influence on the phase boundary sliding(PBS).Electroplates on Zn 5Al alloy impose mechanical hampering effect on SPD.Meanwhile,when Zn 5Al alloy is superplastically deformed in an electric field,inductive surface charges will induce lots of voids on the surface,and thus increase deformation stress,which results in lower strain rate and lower elongation and takes on negative electroplasticity.更多还原