Assessment of Tribological Characteristics of Stir Cum Squeeze Cast AlSi7Mg with x wt % Flyash and 3wt % MoS ₂ Hybrid Composites 2021-28-0260

his research work aims to investigate the effect of flyash and MoS₂ lubricant particles on the tribological properties of AlSi7Mg alloy fabricated through stir cum squeeze casting process. AlSi7Mg alloy is a supreme favourable industrial aluminium alloy owing to its exceptional casting ability, corrosion resistance and good strength to weight ratio. Stir casting is an effective and capable processing route for making aluminum composites with enhanced properties. Additionally, to achieve enhanced properties and a pore-free structure, stir cum squeeze casting processing was used to fabricate aluminium matrix composites. In the experimental investigation, AlSi7Mg alloy was reinforced with 0, 5, 10wt% flyash and 3wt% MoS₂ and processed by stir cum squeeze casting method. Responses such as wear rate and coefficient of friction were determined using a Pin-on-Disc tribometer apparatus under dry sliding conditions with a varying load of 10, 20, 30, and 40N and a constant sliding velocity of 3 m/s to observe the effect of reinforcement and applied squeeze pressure on the tribological characteristics. The results indicate that by adding flyash reinforcement particles and MoS₂ lubricant particles to AlSi7Mg aluminium alloy, the wear resistances tend to increase and coefficient of friction was decreased with respect to increase in wt% of fly ash and MoS₂. Increased weight percentage additions of 10wt% fly ash and 3wt% MoS₂ resulted in a noteworthy enhancement in the wear characteristics. Furthermore, the inclusion of MoS₂ lubricant particles in hybrid metal matrix composites reduces metal-to-metal contact, which leads to an improvement in the tribological properties of composite samples processed under stir cum squeeze casting technique. Combined effect of higher weight percentage of reinforcement addition and squeezing of liquid metal improvises the tribological characteristics of the AlSi7Mg with 10wt% flyash and 3wt% MoS₂ hybrid metal matrix composites than that of the other combinations.