Comparative Study on Mechanical Properties of SiC/Gr &al2O3/Gr reinforced AL6061 hybrid metal matrix composites

Abstract

Silicon carbide / Graphite and Alumina / Graphite reinforced AL6061 Hybrid metal matrix composites are fabricated by stir casting (liquid metallurgy) route. Four samples A,B,C,D with varying proportions in both matrix and reinforcements by fixing graphite proportion (5%) constant for all sampled are prepared. Mechanical properties of all the samples are compared with matrix material (AL6061). Scanning electron microscope is used to examine the microstructural characteristics of the composite samples. Mechanical test results exhibit 3.5% (sample C) increase in the hardness number than the base matrix. But, yield and ultimate tensile strength are reduced with all the reinforcements. Microstructural characterisation clearly depicts the presence of cracks, Agglomeration of reinforcements, cast defects on the surface of prepared composites which leads to poor yield and ultimate tensile strength.