Surface Hardening of AlMg<sub>5</sub>Si<sub>2</sub>Mn Alloy through Multi-Axis Compression Using Max Strain

Abstract

Severe plastic deformation (SPD) processing techniques are applied to polycrystalline metallic materials in order to refine the grain size up to the sub-micrometre or nanometer level. The decrease in grain size to a sub-micrometre level is related to beneficial mechanical properties such as very high strength. The most widely applied SPD method is equal-channel angular pressing (ECAP). In distinction to traditional cold rolling or drawing, SPD techniques frequently employ cyclic strain paths that can lead to an essentially unchanged shape of the material sample after processing. In this paper, multi-axis compression is applied by using the MAXStrain (R) unit to impose cyclic compression in two mutually orthogonal directions. This study is aimed to realize the evolution of microstructure and mechanical properties of AlMg5Si2Mn aluminium cast alloy subjected to multi-axis compression. The microstructure of the alloy in the as-cast and as deformed state was characterized by light and scanning electron microscopy. The results reveal that multi-axis compression has a great influence on the evolution of microstructure and final mechanical properties. The enhanced mechanical properties are associated with the progressive formation of refined microstructure which is heterogeneously distributed across the sample.