Synthesis of fine grained magnesium alloy by severe plastic deformation

Abstract

In the present investigation, AZ31 magnesium alloy has been subjected to equal channel angular pressing (ECAP) to impart severe plastic deformation in an attempt to refine its microstructure. Homogenous grains of average sizes below 1μm were achieved by controlling the number of ECAP passes and processing temperature. The grain refinement mechanism is believed to be the result of accumulative shear strain causing the formation of high angle boundaries and subgrains during ECAP. Dynamic recovery of the Mg grains during ECAP was evident from microstructure observation and was strongly dependent on the processing temperature. Experimental results of the resulting grain sizes to their corresponding yield strength showed good agreement with the Hall-Petch (H-P) relationship. Issues on the effectiveness of such grain refinement in relation to mechanical properties are discussed in this paper. © Institute of Materials Engineering Australasia Ltd.