Mechanism of plastic void growth during superplastic flow

Existing models for plastic hole growth have been re-evaluated in terms of their applicability to superplastic flow. The Cocks and Ashby model is modified to include more properly the effect of void shape, and the effect of simultaneous strain hardening is also discussed. Some new experimental data on the growth of artificial holes drilled in a sheet sample of Coronze 638 are presented and compared with data on the development of general …