Abstract
The present investigation aims to study the microstructure and mechanical properties of (A365/ SiC particulate) MMC produced by stir casting technique. The A356 matrix was reinforced by the addition of 3% SiC ceramic particulate having particle size ranging from 20-90 μm. The SiC particles were added to the molten in the semi-solid state during stirring at rotating speed of 700 r.p.m for duration of 1 minute. The composite was then poured in a preheated metallic mould, after which standard samples were prepared for microstructure and mechanical testing characterization. The results of the study revealed that the consolidation of the SiC and its distribution in the A356 matrix as investigated from the microstructure has increased; the tensile stress from 170 to 195 MPa, compressive yield limit from 156.5 to 190 MPa and ultimate compression stress at 35% strain increased from 350 to 460 MPa. Also macro-hardness of composite material has increased from 72.5 HV for unreinforced alloy to 80 HV, while the elongation% and impact toughness was reduced by 25% and 55% respectively. On the other hand, a dramatic increase in the toughness value for un-notched impact samples of A356 alloy when it cast in SSM (20 J) rather than that when it cast in fully liquid state (6 J).