Investigation on the Effect of Stirring Process Parameters on Particle Dispersion in the Lm25 Sic Aluminium Matrix Composite AMC and its Wear Behavior in As Cast and Heat Treated Condition

Abstract

In the last two decades, Aluminium Matrix Composites (AMCs) have sought significant attention in automotive applications due to its advantages like lightweight (low density), high wear resistance, improved mechanical properties and low coefficient of thermal expansion. In addition, in many cases, aluminium composites are economically competitive with iron and steel castings. newlineAmong the materials of mechanical and tribological significance, aluminium alloy LM25 has sought significant attention due to its good castability. The LM25 is also a promising material in automobile components. Among the particulate reinforcements, silicon carbide (SiC) improves wear resistance as well as mechanical and thermal properties. Also, SiC is not attacked by acid on molten salt up to 800 °C. Thus, aluminium alloy LM25 was selected as matrix material and silicon carbide particles having mean size of 37.58 microns (d50 value) were used as reinforcement phases for development of AMCs. newlineSome high temperature applications of AMCs in the automobile sector consist of moving parts, which are subjected to wear and friction. There is a lack of data on combined effect of load, sliding speed and temperature on tribological aspects in as-cast and heat-treated LM25/SiC AMCs, limiting its applications. This paucity was addressed in the present research work. newlineStirring based liquid metal processing is the widely explored process by researchers for the production of aluminium matrix composites. The dispersion of reinforcement particles is the major challenge in the process. For the development of quality composites, precise control needed on the melting, particle addition and supply of inert gas. Thus, to address these issues a dedicated stir casting setup was developed and its performance was assessed. In addition, the stirring process parameters govern the newline5 newlinedispersion of reinforcement particles in AMCs. The important stirring process parameters are stirring speed, stirrer geometry, stirrer position, and stirring time. In the literature, research w