Modelling of cavitation in two phase superplastic alloys under uniaxial stress systems

Abstract

Abstract Superplastic materials are characterized by their ability to undergo exceptionally large deformation under low stresses. Many alloys, however, are prone to cavitation, which leads to premature failure even though deformation is within the superplastic regime. A model is presented which analyses the evolution of pre-existing cavities in two phase alloys subjected to uniaxial stress systems. It is seen that this model adequately describes the cavitation phenomenon of α–β brasses and microduplex Cu-Zn-Ni alloys in the tensile test. Closure of cavities in the compression test may also be described by this model. The results obtained thus enable the formation of an overall view of the behaviour of a two phase superplastic alloy subjected to the uniaxial tension test, and the difference in cavity evolution of different materials.