A two-dimensional model of creep cavitation failure in copper subject to biaxial stress systems at 250°C

Abstract

Analysis of a two-dimensional polycrystalline model undergoing grain-boundary cavitation by vacancy diffusion shows that the main features of creep failure under biaxial stresses can be simulated for steady loading. It is necessary to assume that cavities greater than the critical size for growth are initiated at the beginning of creep, and that their mean spacing is inversely related to the maximum principal applied stress. Computer-aided simulation of the behaviour of tough-pitch copper compares well with previously reported observations for steady biaxial loading, but the model predictions are found to be inconsistent with results of preliminary tests under variable loading.