Synthesis and Characterization of A356-Sicp Composite Produced through Vacuum Hot Pressing

Abstract

The aim of this research is to analyze the effect of SiC particle addition and heat treatment on the microstructure and mechanical and thermal properties of A356 aluminum alloy–based metal matrix composite. Aluminum alloy powder in the size range 25–50 µm and SiC particles of 1 µm average size in 0, 5, 10, 15, and 20 volume percentages were used as raw materials. Powders were blended in a ball mill and then sintered in vacuum hot press. The hot pressed composites were heat treated using T6 heat treatment. Microstructure analysis was carried out to assess the distribution of the SiC particles in the Al matrix. Hardness, tensile strength, compressive strength, and coefficient of thermal expansion (CTE) have been measured both on base alloy and composite materials, before and after the heat treatment. The result showed that addition of SiC particles improved the hardness, compressive strength, and decreased the CTE on both heat treated and as hot pressed samples. However, the tensile strength increased with increase in SiC particles in the range 5 to 15% and then decreased for composite with 20% of SiC particles.