Fracture analysis of AZ6-F magnesium composite materials at quasi-superplastic state

Micromechanisms of fracture of AZ61-F composites in the zone of quasi-superplastic deformation were analysed 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 x 10(-2) to 1 x 10(-4) s(-1), a significant growth of ductility was observed. The mean dimples diameter of the ductile fracture decreased with decreasing strain rate. The grain size of 0.7 mu m was reached by severe plastic deformation using equal channel angular pressing (ECAP). Secondary Mg17Al12 and Al2O3 phases were identified. The maximum strain was obtained at the temperature of 473 K and strain rate of 1 x 10(-4) s(-1).