Transmission of Deformation Twins across Grain Boundaries in Nanocrystalline and Ultrafine-grained Metals

摘要

Transmission of nanoscale deformation twins across grain boundaries in nanocrystalline and ultrafine-grained metallic materials is theoretically described. The energy and stress characteristics of twin transmission across grain boundaries in nanocrystalline and ultrafine-grained metals are revealed. It is found that for small twin thicknesses, the critical stress for twin transmission in Cu is close to the typical values of the yield stress, and so twin transmission can actually occur in the course of deformation of nanocrystalline and ultrafinegrained Cu.