锌铝共析合金的超塑性变形组织特征

来源期刊：中南大学学报(自然科学版)1996年第4期

论文作者：罗兵辉 周善初

文章页码：452 - 455

关键词：超塑性变形; 晶界滑移; 孔洞; 位错

Key words：superplastic deformation; grain boundary sliding; holes; dislocation

摘    要：用电镜等手段对室温下超塑性变形中的Zn－22%Al共析合金的组织变化进行了观察,发现在该合金的α相(富Al相)+β相(富Zn相)2相组织中,在三叉晶界存在亚微观破坏区(破坏了晶粒间的连续性)和显微孔洞,在α,β晶界的某些区域存在条纹带,某些晶粒内部存在大量位错及其缠结.据此,证实该合金超塑性变形的主要机制是新晶粒挤入及晶界滑动.孔洞和位错运动松弛晶界活动引起的应力集中,能协调晶界滑动的连续进行.条纹带是晶界迁移的结果.

Abstract: In this paper,the structure change of a superplastic Zn-22%Al eutectoid alloy at the room temperature has been investigated and discussed in terms of optical and electron microscopy. It is shown that microregions and microholes exist in the triple points of grain boundary. The striped bands exist in some grain boundaries and many dislocation within some grains. The main mechanism of superplastics is the grain squeezing and grain boundary sliding. The hole and movement of dislocations relax the stress concentration because of grain boundary sliding. The striped bands are the result of grain boundary sliding.