Influence of temperature and strain rate on superplasticity kinetics of composite AZ61-F magnesium materials

Abstract

Micromechanisms of fracture of AZ61-F composites in the zone of quasi-superplastic deformation were analyzed and quantified in this work. Deformation of AZ61-F magnesium alloys with 1 wt.% of Al2O3 phase was tested at a temperature of 473 K and different strain rates. It was shown that at the temperature of 473 K and the highest strain rate applied from 1× 10−2 to 1 × 10−4 s−1, a significant growth of ductility was observed. The mean dimples diameter of the ductile fracture decreased with the decreasing strain rate. The grain size of 0.7 μm was reached by severe plastic deformation using equal channel angular pressing (ECAP). Secondary Mg17Al12 and Al2O3 phases were identified. The maximum strain was reached at the temperature of 473 K and strain rate of 1 × 10−4 s−1.