The Role of Cavitation in Superplasticity

这项研究的目的是研究超塑性变形过程中内部空洞形成的基本机制。实验将集中在：锌-22%铝，铝-33%铜，一种含富钴析出物的铜合金，以及一种铝锂合金。这项工作的中心目标包括：确定裂纹缓慢扩展的微观结构基础；检查微腔如何沿张力轴相互连接；确定是否存在空腔成核的临界应变率；以及开发定量的空腔分布测量程序。这项工作将涉及广泛的扫描/透射电子显微镜和定量金相研究。

The objective of this proposed research is to investigate the basic mechanisms by which internal cavities develop during superplastic deformation. Experiments will concentrate on: Zn- 22% Al, Al-33% Cu, a Cu alloy containing Co-rich precipitates, and an Al-Li alloy. The central objectives of this work include: determining the microstructural basis for slow crack growth; examining how microcavities interlink along the tensile axis; determining if a critical strain rate exists for cavity nucleation; and, development of a quantitative cavity distribution measurement procedure. This work will involve extensive scanning/transmission electron microscopy and quantitative metallographic studies.