Microstructure, mechanical properties and wear behaviour of the AZ91–Mg2Si–SiC hybrid composites

Abstract

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.