A comparison of failure prediction methods for superplastic deformation

This paper presents a comparison between a number of different failure prediction methods for superplastic forming processes. Attention is limited here to superplastic forming of Ti-6Al-4V at 927C. The failure prediction methods considered include the flow localisation factor approach, forming limit curves based on void growth models, such as the Rice and Tracey model and the Cocks and Ashby model, and a recently-presented superplastic forming limit diagram (SPFLD) approach. Finite element modelling of the forming process is employed to assess the failure prediction methods and the predicted results are compared with available test data.