EVALUATION OF MECHANICAL BEHAVIOUR AND EFFECT OF PARTICLE SIZE ON LM26/Gr METAL MATRIX COMPOSITE

Abstract

In automotive industries, Aluminium cast alloy (LM26) is well-renowned material in the fabrication of pistons for both diesel and petrol engines for its superior casting and mechanical properties. However, diminishing strength at higher temperatures drives metal matrix composites in cast alloys. The present study focused on the impact of naturally available ceramic particles Garnet on the microstructure and mechanical properties of Aluminium cast alloy (LM26). Samples were fabricated with varied Garnet (Wt. % of 3, 6, 9, and 12) by dual step stir casting technique. Two different particle sizes (400µm and 250µm) were incorporated to determine the effect of particle size on composite mechanical behaviour. Scanning electron microscope images unveiled the dissemination of ceramic particles inside the cast alloy matrix. It was found that ultimate tensile strength, yield strength, and impact strength were increased up to a certain Garnet percentage and started diminishing with the rise in particulate fraction for both particle sizes. However, the increase in hardness value indicates the brittleness of Metal matrix composite with the increase in ceramic reinforcement. Validation of Experimental results with theoretical values was also discussed.