Superplastic flow and failure in a fine-grained 7475 al alloy

Abstract

An elongation of 907% has been achieved in a fine-grained superplastic 7475E Al alloy by deformation at 517 °C at a strain rate of 2 × 10 −4 s −1. Appreciable grain growth was evident only after an elongation of 500% was exceeded thereby inducing localization of necking. A considerable amount of dislocation-particle interactions has been observed during superplastic deformation. The combined effect of grain growth, localized necking, and dislocation-particle interactions leads to the nucleation and subsequent growth of cavities.