Microstructure evolution and simulation study of a duplex Mg-Li alloy during Double Change Channel Angular Pressing

The dual-phase Mg-9Li-3Al-2Sr-2Y alloy was extruded at 553 K using Double Change Channel Angular Pressing (DCCAP) with an extrusion ratio of 17. The commercial code DEFORM-3D was used to develop a numerical model for deformation of the investigated material and the strain distribution, damage and grain shape evolution were predicted. The accurate computation of the material flow and deformation was performed, of which the results showed good agreement with microscope observations and micro-hardness measurements on the deformed billet and extrudate. Results suggest that dynamic recrystallization (DRX) occurs during the deformation and leads to grain refinement during the DCCAP process. The tensile strength and elongation after fracture in middle part of the extrudate show optimum values of 246.6 MPa and 19.9%, respectively. (C) 2015 Elsevier Ltd. All rights reserved.