The nucleation and growth of voids in a material containing a distribution of grain-boundary particles

Abstract

Void growth is analysed when a grain boundary contains a distribution of second phase particles. The rate of void growth is determined by the ease with which material can plate out around the particles or the rale at which the material surrounding the particles can deform by power-law creep. At low applied stresses, stress is concentrated onto the particles which can act as nucleating sites for new cavities. The stress at a particle is a function of its size, and increases as the area fraction of voids increases. A new cavity can nucleate once this stress reaches a critical value, and because materials contain a distribution of particle sizes, nucleation occurs continuously during the course of an experiment.