Production and abrasive wear characterization of SiC/AZ91 Mg matrix composite processed by a stir casting method

Magnesium alloy (AZ91) matrix composites reinforced with various volume fractions of SiC particulates were processed. A stir casting process has been employed under an inert atmosphere to produce magnesium matrix composites. This process leads to a complete wetting of SiC particles in the molten magnesium. Microstructural features of the composites are analysed by scanning electron microscope (SEM) and energy dispersion X-ray analyses, some microstructure features are such as SiC particles distribution and the interface between the magnesium matrix and SiC. The SiC/AZ91 alloy composite shows a refined matrix structure of the composite compared to the matrix alloy, a uniform SiC distribution in the matrix and that no reaction takes place during the synthesis of the magnesium alloy matrix composites between the oxidized SiC and the molten magnesium. Results of the mechanical properties revealed an increase in hardness value, maximum tensile strength and 0.2% yielding strength. Results of the mechanical properties revealed an increase in hardness value, maximum tensile strength and 0.2% yielding strength. Due to the addition of SiC in AZ91 matrix alloy, the strength is increased, i.e., an increase in dislocation density and a reduction of matrix grain size. Finally, during the examination of fracture surfaces, the SiC/matrix shows matrix cracking, particle cracking and extent of fine dimples over the surfaces.