Elongated nanoscale voids at deformed special grain boundary structures in nanocrystalline materials

摘要

A special micromechanism for the formation of elongated nanoscale voids at grain boundaries (GBs) in deformed nanocrystalli materials is suggested and theoretically described. Within our description, the formation of nanoscale voids represents a slow (dif sion-controlled) process driven by release of the elastic energy of GB disclination configurations formed due to GB sliding. It is demc strated that the nucleation of elongated nanoscale voids at GB disclination dipoles occurs as an energetically favorable process deformed nanocrystalline Ni and Al_2O_3 (sapphire) in wide ranges of their parameters.