Large strain behaviour of a superplastic copper alloy—II. Cavitation and fracture

A quantitative study of cavitation damage and fracture of a superplastic copper alloy, Coronze 638, has been made. Cavities are found to nucleate at large particles present in the form of stringers. The size and shape of cavities, as well as the level of damage up to fracture are essentially independent of strain rate over regions I and II of the σ−ϵ curve, as are the true strain to fracture and the development of t instabilities. As the strain …