Comparative study of the deformation behavior of hexagonal magnesium-lithium alloys and a conventional magnesium AZ31 alloy

Specimens of a conventional magnesium AZ31 alloy and a binary alpha-solid solution Mg4Li alloy with similar starting textures and microstructure were subjected to plane strain deformation under various deformation temperatures ranging from 298 K to 673 K. Lithium addition to magnesium exhibited remarkable room temperature ductility improvement owing to enhanced activity of non-basal slip, particularly, < c + a >-slip mode. Furthermore, the addition of lithium to magnesium seemed to reduce the plastic anisotropy, typical for commercial magnesium alloys. This was evident in the flow curves and texture development obtained at 200 degrees C and 400 degrees C. At 400 degrees C prismatic slip gains strong influence in accommodating the imposed deformation. In terms of thermal stability against microstructure coarsening at elevated temperatures, the lithium containing alloy undergoes significant grain growth following recrystallization. (C) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.