The effect of a non uniform void distribution on grain boundary void growth during creep

The effect of the distribution of voids over a grain boundary facet, on the void growth process, has been modelled. Assuming the grains to behave as rigid slabs which move apart during cavitation at a uniform rate, any non-uniformity of void spacing results in stress redistribution over the facet. The net result is a decrease in the overall damage rate compared to that expected for a uniform array at the same damage level, and a large variation in the growth rate of individual voids. The effect increases as the distribution of voids becomes clustered. The model shows that the effects of void distribution are significant and that they must be included in any attempt to predict times to failure.