Experimental Investigations on Effect of Silicon Carbide on Microstructure and Mechanical Properties in Mg-3 wt% Al Alloy Matrix Using Powder Metallurgy

In this work, Silicon Carbide (SiC) reinforced Mg-3 wt% Al alloy matrix composites was developed with varying SiC content of 3, 6 and 9 wt% by using Powder Metallurgy (PM). Each composite sample was ball milled by using planetary ball mill with a rotational speed of 120 rpm for 3 h. Then the milled powders were compacted in hydraulic press. Sintering was done in an Argon controlled atmosphere at a temperature of 450 °C. The morphology and composition of the composite powders and sintered composites was studied by using SEM and EDAX. Even spreading of SiC particles in matrix were obtained for the composite samples. XRD analysis of milled and sintered composite ensured the absence of intermetallic compounds. Experimental density, porosity, hardness, compressive strength and corrosion rate were analysed for the alloy and composites. The addition of SiC improved the density, CS and hardness of the composite. The highest CS was witnessed for the sample contain 9 wt% of SiC as 169 MPa and hardness as 66.9 Hv. The lowest corrosion rate was observed for the Mg- 3 wt% Al- 9wt. % SiC composite as 0.000142 mm/year.