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