Recent void shrinkage models and their applicability to diffusion bonding

Abstract

Recent void shrinkage models are reviewed and refined. The role of surface selfdiffusion is discussed for modelling void shrinkage by selfdiffusion along the void surface and bond interface. The refinement of the existing models makes it possible to discuss the effect of void crushing by power law creep, the validity of combining models of diffusion and creep, and the applicability of the existing models. The discrepancies between the various models are demonstrated by reference to the stress dependence of void shrinkage rate (log–log plots). The void crushing rate due to power law creep of the surrounding matrix is highly dependent on the degree of bulk deformation, i.e. the severity of bulk constraint. The applicability of the combined models of creep and diffusion are therefore limited by this condition.

MST/1502