SUPERPLASTICITY OF AL-LI-MG ALLOYS PROCESSED BY EQUAL CHANNEL ANGULAR PRESSING
The results of experimental studies of superplasticity of 1420 Al-Li-Mg alloy processed by equal channel angular pressing are presented. Optimum temperatures and strain rates are determined where the alloy has a large superplastic elongation of more than 2000%, high coefficients of the strain rate sensitivity of more than 0.45 and the values of the activation energy lower than 70 kJ/mol. The observed effect of the nonlinear dependence of superplastic elongation on the grain size is explained on the basis of the proposed theoretical model.