Effect of Ca addition on the plastic deformation behavior of extruded Mg-11Li-3Al-1Sn-0.4Mn alloy

Abstract Effects of Ca addition on the microstructure and mechanical properties of as-extruded Mg-11Li-3Al-1Sn-0.4Mn-xCa alloys with x = 0 and 0.8 were investigated. The Ca addition on the Mg-11Li-3Al-1Sn-0.4Mn alloy can lead to no change in the constituent phases, which consist of β -Li, α -Mg, MgLi 2 Al and MgLi 2 Sn. However, the microstructure obtained after the extrusion process clearly exhibits different morphologies, of which Ca free alloy shows homogeneously distributed intermetallic compounds and Ca containing alloy display well-arranged intermetallic compounds along the extrusion direction. From these microstructural evolutions, even though the tensile strength decreased, the tensile elongation was significantly improved from 35.1 to 88.6%. The effect of Ca addition on the microstructural evolution and increased plastic deformability have been discussed using grain refinement, grain boundary sliding and micro crack propagation.