Cooperative grain boundary sliding in materials with non-uniform microstructure

摘要

One of the important prerequisites for superplastic (SP) performance is a uniform fine grained micro-structure [1]. It has been reported recently [2-4] that cooperative grain boundary sliding (CGBS), i.e. sliding of grain groups, is an important mechanism of SP flow in fine grained materials. Meanwhile, the microstructure of real commercial SP materials is often non-uniform: coarse grains might co-exist along with fine grains.