Investigation of mechanical properties of SiC particle reinforced Aluminium A356 / LM25 alloy composite

Abstract

Aluminium Silicon alloy composites A356 - SiCp were prepared by varying weight percentage of Silica Carbide particle (SiCp) content in the Al- Si alloy by stir casting method and subjected to T6 heat treatment. The effects of SiCp (2% 4% and 6% weight fraction) in the A356 alloy composite on the basic mechanical properties like tensile strength, percentage elongation, compressive strength and impact strength were investigated. The cast A356 base alloy before heat treatment and after heat treatment were also assessed for its basic microstructural and mechanical properties. The virtues of post heat treatment effects such as release of residual stresses, grains refinement, precipitation strengthening and the phenomenal transformation of eutectic Si particles to spheroidal structures, have contributed to enhance the mechanical properties considered. The compressive strength of the composites has increased with increase in SiCp wt.%. The tensile strength of the composites has increased and is maximum for 4% reinforcement but for 6% SiCp inclusion there is slight decrease in the tensile strength when compared to 4% SiCp. The elongation property and impact strength values have been observed to be drooping with increase in the SiCp wt. % content in A356. A comprehensive discussion is made based on the analysis of the strengthening to weakening behavior of the strength, ductility and impact toughness of the fabricated composite.