The effect of Ca addition on microstructure and mechanical properties of extruded AZ31 alloys

Abstract

Evolution of microstructure and tensile properties of extruded AZ31 alloys through Ca addition have been systematically investigated in this paper. Results show that Al–Mn and Al2Ca phases scattered along extruding direction exist in extruded AZ31-xCa (0.5 and 1 wt%Ca) alloys. AZ31-1 wt%Ca alloys exhibit finer microstructure with mean grain size of ~2.79 μm in comparison with AZ31-0.5 wt%Ca alloys, which is mainly related to the dynamic recrystallization (DRX) and the inhibition of grain coarsening by Al2Ca phase. In addition, the increased Ca content weakens the {0001} basal texture of extruded AZ31 alloys owing to the formation of Al2Ca phase. The comprehensive mechanical properties of extruded AZ31 alloys have an obvious improvement by adding Ca element owing to the grain refinement strengthening, second phase strengthening and texture strengthening.