Analysis of constrained cavity growth during high temperature creep deformation

Abstract

A general model for constrained cavity growth is developed for cavitation during creep deformation. The model incorporates the effect of the separation between cavitated facets, the contributions of local power-law creep in the cavitated regions of a specimen, and the possibility of coupled cavity growth. A detailed analysis of the model reveals that, during constrained cavity growth at low stresses, interaction effects enhance the cavity growth rates when L/d<10, where L is the separation between the cavitated facets and d is the grain size. An assessment of the stress redistributions occurring during cavity growth indicates that constrained cavity growth may lead to increases in the specimen creep rate by significantly increasing the stress in the uncavitated regions of a specimen when L/d<5. It is also demonstrated that, under the appropriate limiting conditions, the present general model gives results similar to those obtained in previous studies on constrained cavity growth.