Microstructure,mechanical properties and wear behaviour of the AZ91–Mg 2 Si–SiC hybrid composites

The present study investigates the effect of different amounts of SiC particles on the microstructure, mechanical properties and wear behaviour of the cast and extruded AZ91–Mg₂Si composite. The microstructural analysis of the cast samples showed the primary α-Mg, semicontinuous networks of the Mg₁₇Al₁₂ intermetallics and scattered Mg₂Si and SiC particles. The hot extrusion resulted in a refined grain structure and homogenously distributed particles. More SiC particles had a positive influence on the microstructural refinement and decrement of the grain size. Increasing the SiC particles improved the hardness and compressive strength and decreased compressive elongation. Furthermore, the wear tests exhibited that more SiC particles enhanced the wear properties. However, at the highest loads, the extruded composite with large SiC particles displayed weak wear resistance.