The study of mechanical and tribological properties of dual size silicon carbide particles reinforced A356 metal matrix composite produced through modified squeeze casting

The duel sized silicon carbide (SiC) particles are reinforced A356 metal matrix composite is casted through modified squeeze casting technique by varying SiC percentage viz 1 %–5 % by weight. The tensile strength and hardness were conducted via Universal Testing Machine (UTM) and Brinell hardness testing machine respectively; the dry slide wear behaviour of the samples was analyzed using pin-on-disc test setup. The microstructure of the composite and the wear surface is analysed using scanning electron microscopy (SEM). Sample S5, consisting of 4 % SiC with 80 µm particle size and 1 % SiC with 160 µm particle size, exhibited enhanced properties compared to the as-cast material. The improvement in mechanical strength and hardness can be attributed to the effective densification of the silicon carbide particles within the composite. Tribological performance was evaluated using a Pin-on-Disc apparatus. Tests were carried out by varying load (10 N, 20 N, and 30 N), speed (500 rpm, 750 rpm, and 1,000 rpm), and duration (4, 8, and 12 min) to study their influence on wear rate across various sliding distances. The testing was conducted for sliding length 300 m. SEM image analysis of the worn surfaces revealed intensive adhesive wear behavior. The dual-sized silicon carbide reinforcement (4 % of 80 µm and 1 % of 160 µm) demonstrated superior wear resistance compared to the base alloy. Microstructural examination further indicated minimal delamination, negligible porosity, and the absence of blowholes in the S5 casting. Additionally, the presence of mechanically mixed layers (MMLs) was verified, which was further associated with an increased accumulation of iron within the hybrid composite.