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 beta-Li, alpha-Mg, MgLi2Al and MgLi2Sn. 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 micro structural 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. (C) 2016 Elsevier B.V. All rights reserved.