The feasibility of vacancy condensation being the void-nucleating mechanism which underpinned ductile fracture by void growth and coalescence in single crystals at room temperature was considered. The vacancies were assumed to be generated mainly by the dragging of intersecting jogs. The equations which governed the rate of void growth via vacancy condensation were derived, and were used to monitor the evolution of vacancy concentrations and void sizes. It was found that, when pipe diffusion was taken into account, the time that was required for the nucleation of a macroscopic void in the near-tip region was of the order of 60s. This was well within the time-scale of quasi-static fracture tests.

A.M.Cuitiño, M.Ortiz: Acta Materialia, 1996, 44[2], 427-36