A STUDY ON THE EFFECTS OF HYBRID (SIC- PSSA) NANO SIZED REINFORCEMENT ON MECHANICAL AND TRIBOLOGICAL BEHAVIOUR OF AL ALLOY-BASED METAL MATRIX COMPOSITE PRODUCED BY ULTRASONIC ASSISTED STIR CASTING

Abstract

This study focuses on the effects of a hybrid reinforcement consisting of nanosized particles of Palm Sprout Shell Ash (PSSA) and silicon carbide (SiC) on the mechanical and tribological properties of the Al-Cu-Mg alloy. Hybrid reinforced composites with different weight percentages of SiC and PSSA (0:0, 0:4, 1:3, 2:2, and 4:0 wt.%) were prepared using the ultrasonic-assisted bottom-poured stir casting technique. SEM and EDS were used to characterize the hybrid composite made of Al-Cu-Mg alloy. Optical and SEM microstructural analyses demonstrated an even distribution of SiC and PSSA nano-reinforcements within the matrix. EDS analysis revealed SiC and PSSA reinforcement in the matrix. The mechanical properties (tensile, flexural, and impact strength) and wear properties of the composites and alloy were evaluated according to the ASTM standards. The hybrid reinforced composites displayed remarkable results compared with the base alloy. Among all composites, the 2:2 wt.% SIC and PSSA hybrid reinforced composite exhibited a significant enhancement in both tensile strength and flexural strength, with a 29.15% increase in tensile strength and a 27.64% increase in flexural strength. However, the inclusion of these reinforcements led to a declined in ductility and impact strength of the Al-Cu-Mg alloy composite. Maximum reductions in ductility and impact strength were observed in the 0:4 wt.% SiC and PSSA-reinforced composites, with decreases of 47.67% and 3.56%, respectively. For the 2:2 wt.% SiC and PSSA composites, these reductions were 23.64% and 3.16%, respectively. The SEM analysis of the fractured surfaces of the composites tested for the mechanical properties revealed evidence of both ductile and brittle fracture mechanisms in the tensile, flexural, and impact tests. The wear behaviour of the prepared samples was evaluated, and all composites exhibited superior performance compared with the base alloy, demonstrating adhesive and abrasive wear mechanisms and varying coefficients of friction.