Characteristics Study of Mechanical and Tribological Behaviour of Gr/Sn Dispersed Al-7Si Alloy Matrix Composite Processed Through Bottom Pouring Stir Casting Technique

Abstract

Abstract Among numerous techniques to manufacture Aluminium metal matrix composites, the stir-casting route is employed for mass production because of less expensive. In this work, Al-7Si alloy-based composites reinforced with 10wt% graphite and x wt% of tin (x = 0, 2.5, 5, 7.5 and 10) microparticles are manufactured through the bottom pouring casting route. This study deals with the various effect of the mechanical properties, and wear resistance of Gr, and Sn particulates reinforced Al-7Si alloy matrix composite. The added Sn metal powder up to 7.5 wt.% was diffused in the lattice of hypo eutectic Al-7Si alloy and formed a solid solution. The hybridization of Sn with graphite in Al-7Si alloy matrix brought significant enhancement in the tribological and mechanical properties of the composites. The ductile mode of fracture in all the composites with tear ridges and dimples was noted. The wear rate and the coefficient of friction of the composites were decreased with the addition of Sn metal powder in the material system. The Sn metal powder surfaced during the wear process and formed a thin mechanically mixed tribo layer and reduced the friction. The thin mechanically mixed tribo layer at the interface restricted the direct contact of asperities in the mating surface and reduced the wear loss. Adhesive wear was found to be active in the composites with Sn metal powder.