Deformation Mechanisms of Nanostructured Metallic Materials

摘要

In this study, an account of the deformation mechanisms and mechanical properties of metallic nanostructured materials (NSMs) using the phase mixture model is given. It is based on recent modelling that appears to provide a conclusive description of the phenomenology and the mechanisms underlying the mechanical properties of NSMs. Common to the proposed models is the concept of a 'phase mixture' in which the grain boundaries are treated as a separate phase. The volume fraction of this 'phase' may be quite appreciable in a NSM. Based on the theoretical model that provides an adequate description of the grain size dependence of plasticity covering all grain size range from coarse down to the nanoscale, the tensile deformation response of NSMs, especially focusing on the deformation mechanisms was investigated. In particular, newly proposed deformation mechanism maps with axes of strain rate, grain size and temperature are presented.