Severe plastic deformation of magnesium alloy AZ31 at low temperatures

Abstract

Equal channel angular pressing (ECAP) is used to cause severe plastic deformation in solid metals with a view to obtaining ultrafine grained materials. In the present investigation, an extruded Mg alloy, AZ31, was processed by ECAP at temperatures as low as 100°C and pressing speeds in the range of 0.2-2 mm/min with an applied back pressure at the exit channel. Up to 8 passes were carried out to achieve large accumulated plastic strain and uniformity of the microstructure. The initial grains of > 20 μm in size were significantly refined to < 1 μm and the corresponding values of both microhardness and macrohardness increased with decreasing grain size. The application of a back pressure and a..