Effect of Equal Channel Angular Pressing on the Microstructure and Mechanical Properties of an Mg-5Sn Alloy

An Mg-5Sn alloy was processed by equal channel angular pressing (ECAP) for different passes (4P, 8P, and 12P), and the microstructure evolution and mechanical properties were investigated. The grain size, amount of Mg2Sn precipitates, and texture of ECAP alloys depend on the number of passes. The ECAP 8P alloy has the finest grains and largest area fraction of Mg2Sn particles, followed by the ECAP 12P alloy. The ECAP 4P and 8P alloys exhibit basal textures tilted towards transverse direction (TD), whereas the ECAP 12P alloy shows basal texture with the c-axis of the grains parallel to the extrusion direction (ED). ECAP alloys show superior strengths compared to the as-cast alloy, mainly attributed to fine grain strengthening, precipitation strengthening, texture strengthening, and dislocation strengthening. The ultimate tensile strength (UTS) increases while the elongation (EL) decreases with increasing ECAP pass.