Phase transitions in superplasticity

Existing ideas about reasons for the occurrence and phenomenology of development of the superplasticity effect are analyzed. It is shown that within the scope of the thermodynamic approach superplasticity depends on a diffuse phase transition accomplished with heating and deformation. Traditional evaluation of super-plasticity from the value of the rate sensitivity factor is considered. Conditions are determined which should be fulfilled with transfer of material into a super-plastic condition, in particular for wrought aluminum alloys without a previously prepared structure.Translated from Problemy Prochnosti, No. 10, pp. 50–54, October, 1990.