Fabrication and dry sliding wear analysis of centrifugally casted A 356-10% SiCp functionally graded metal matrix composites at different rotational speeds. Issue 1 (March 2021) - Mohan, Arjun
Abstract: Functionally graded materials (FGMs) are advanced composite materials characterized by their variation in the composition or microstructure in a specific direction. The composition of FGMs is continuously varying. The desired properties can be achieved in a single bulk material of FGM which makes them especially applicable for mechanical and tribological applications. Using a vertical centrifugal casting machine fabrication of aluminium A 356-SiCp functionally graded metal matrix composites (FGMMC) were done. 10% by volume of SiCp particle were taken. An average size of 34 μm is chosen for additive SiCp, so that dispersed particulate matter in matrix of A-356 will enhance mechanical and tribological properties such as wear resistance, ultimate strength and hardness. The castings were carried out at 1100 rpm, 1200 rpm, 1400 rpm, 1550 rpm, 1700 rpm and 1950 rpm of the machine. The microstructural analysis projects a good gradation at 1700 rpm. The observations are validated using hardness analysis. Dry sliding wear behaviour of FGMMCs fabricated at rotor speeds of 1550 rpm, 1700 rpm and 1950 rpm were done. Hardness improvement at outer radial position than that of inner radial position of FGMMCs are 1.19, 1.29, 1.35 and 1.54 times at speeds 1400, 1550, 1700 and 1950 rpm of the machine respectively. The casting at 1700 rpm showed a good gradation at transition region compared to others. Wear resistance at outer surfaces of FGMMCs are improved with the presence of SiCp at the expense of COF.