Effect of Impurities on Superplastic Flow and Cavitation

本研究的目的是研究超塑性流动， 细粒金属合金。特别是， 蠕变时晶界处的杂质原子偏聚， 研究了Zn-22%Al和Pb-62%Sn合金中的空化现象。特别 将注意界定负责这些问题的机制， 对于观察到的蠕变应力阈值，并确定 细晶中形变与空洞生长的关系 合金.预计这项研究计划的结果 将增强对杂质原子在原子核中作用的理解。 超塑性合金的变形、可成形性和断裂。

The objectives of this research is to study superplastic flow in fine grained metallic alloys. In particular, the effects of impurity atom segregation at the grain boundaries on creep and cavitation in Zn-22%Al and Pb-62%Sn will be investigated. Special attention will be given to delineating the mechanisms responsible for the observed creep stress threshold, and to determining the relationship between deformation and cavity growth in fine grain alloys. It is anticipated that the results of this research program will enhance the understanding of the role of impurity atoms in the deformation, formability, and fracture of superplastic alloys.