Paper Title
Mechanical Properties Enhancement of Al-Si (ADC12) Alloy by Heat Treatment

he present work deals with the effect of heat treatment on the mechanical properties Al-Si (ADC12) alloy. The mechanical properties such as tensile strength, compressive strength, hardness and impact strength of the composites in as cast and heat treated condition were studied in order to achieve the maximum properties. Microstructural examination of the alloy in as cast and heat treated condition was carried out to observe the effect of aging. X-ray diffraction of the alloy in as cast and heat treated condition was done to know the phases present in the material. The fracture surface study was done to ascertain the type of fracture taking place in the alloy. It is observed that there is a substantial improvement in the mechanical properties of the alloy due to heat treatment as compared to the as cast alloy. The microstructural study of the cast alloy shows aluminum dendrites with dendretic arm spacing in the range of 25 microns. The eutectic silicon solidifies in the inter-dendretic region and around the dendrites. On heat treatment the plate shaped eutectic silicon is fragmentated into spherical shape. X-ray diffraction analysis shows major peaks of aluminum and minor peaks of intermetallic phases such as CuAl2, Al2CuMg and Mg2Si in as cast as well as in heat treated condition. Tensile fracture surface study shows the fracture is taking place by inter- granular manner (crack propagation along the grain boundary) and morphology of dendrites in the fracture surface. Keywords— Al-Si alloy; heat treatment; tensile strength; compressive strength; hardness; impact strength; tensile fracture.