Properties inhomogeneity of AM60 magnesium alloy processed by cyclic extrusion compression angular pressing followed by extrusion

A new severe plastic deformation (SPD) technique for improvement of the metallurgical properties of the magnesium alloys is presented. In this process, a cyclic extrusion compression angular pressing (CECAP) process is followed by an extrusion step in the outlet playing the role of additional back pressure. Therefore, more uniform and enhanced mechanical properties are expected in comparison with equal channel angular pressing (ECAP). In order to evaluate the effectiveness and capabilities of this new method, an AM60 magnesium alloy was processed. Finite element results exhibited a significant increase in strain values as well as uniform strain distribution for the new method. In addition, ~110% increase in compressive stress was observed in new method compared to the conventional ECAP. Experimental results revealed a noticeable increase in the hardness and strength of the specimens processed by the new technique as a result of the formation of finer grains and more homogeneous microstructure with good distribution of refined β-phase along the boundaries. It may be concluded that the new process is very promising for future magnesium alloy products.