Equal Channel Angular Pressing of a Mg–3Al–1Zn Alloy with Back Pressure

Abstract

Abstract An extruded Mg–3Al–1Zn alloy bar is subjected to 1–4 passes equal channel angular pressing (ECAP) with or without 125 MPa backpressure via route Bc at 200 °C. Both strength and ductility are significantly increased after ECAP with backpressure; this is in strong contrast to the case of ECAP without backpressure, where significant improvement in ductility is accompanied by obvious decrease in yield strength from texture softening. Compared to ECAP without backpressure, much enhanced grain refinement, and the split of the dominant texture component of (0002) pole were observed with scatter intensity peaks in the case after ECAP with backpressure. This turns out to be resulted mainly from the activation of new slip system together with enhanced dynamic recrystallization under the effect of backpressure. The improvement of both strength and ductility in Mg–3Al–1Zn alloy through ECAP with back pressure provides a better approach to meet the engineering requests on comprehensive performance of this light alloy.