A study of intergranular cavity growth controlled by the coupling of diffusion and power law creep

A technique based on pre-creeping and sintering is used to create large, widely spaced cavities at grain boundaries in copper. The size and spacing of the cavities is such that cavity growth is expected to be controlled by the coupling of diffusion and power law creep. The rupture properties of these pre-cavitated samples are studied over a range of stresses and temperatures and the results are compared with the predictions of various theoretical treatments of cavity growth. The stress and temperature dependence of rupture can be described using an analysis of the type suggested by Chen and Argon, provided that the diffusional length is based on the ligament stress rather than the applied stress