A comparative study on the microstructure, texture, and mechanical properties of extruded Mg-9Li and Mg-9Li-0.3Ca alloys

The microstructure, texture and mechanical response of extruded Mg-9Li and Mg-9Li-0.3Ca were examined. The results indicated that the Ca addition resulted in the formation of micro-sized Mg2Ca and a reduction in volume fraction of alpha phase. Besides, compared with Mg-9Li, Mg-9Li-0.3Ca exhibited a higher degree of dynamic recrystallization (DRX) and a lower volume fraction of subgrains, which are mainly attributed to the particle stimulated nucleation (PSN) effect and stacking fault energy (SFE) reduction caused by Ca addition. Texture analysis results demonstrated that both {0002}< 10 1 0 > basal texture of alpha phase and alpha-fiber texture of beta phase were weakened with Ca addition, whilst it was reversed for the {11 2 2}< 11 23 > pyramidal texture of alpha phase. Finally, under the synergistic action of microstructure and texture alterations induced by Ca addition, Mg-9Li-0.3Ca displayed a higher elongation (EL) and strain hardening capacity while a lower yield strength (YS) and ultimate tensile strength (UTS) than Mg-9Li in tension along extrusion direction (ED).