Formation of microstructure and the superplasticity of Al–Mg-based alloys

Abstract

The influence of a 3–10% content of magnesium in Al–Mg–Mn(Cr) alloys on the characteristics of the microstructure of sheet blanks and their superplasticity has been examined. It has been shown that the minimum size of grains and the best superplasticity are characteristic of the alloy that contains about 7% magnesium and is additionally alloyed simultaneously with manganese and chromium. An increase in the content of magnesium leads to the formation of conglomerates of particles of a chromium–manganese phase and, as a result, to a coarsening of the grain structure and a deterioration of superplasticity.