An Experimental Study on Tensile and Hardness Properties of Fsw 2024 Aluminium Alloy Hybrid Composites Reinforced with Sic and Mos₂

Abstract

This study investigates the tribological and mechanical behavior of hybrid composites fabricated from friction stir welded (FSW) 2024 aluminum alloy reinforced with varying proportions of silicon carbide (SiC) and molybdenum disulfide (MoS₂) particles. The composites were prepared using the stir casting method, incorporating SiC (up to 10 wt%) for its superior hardness and MoS₂ (up to 6 wt%) for its self-lubricating properties. FSW was performed under optimized parameters—1000 rpm rotational speed and 70 mm/min travel speed—to ensure defect-free joints and uniform particle dispersion in the weld zone.

The addition of SiC contributed to grain refinement and enhanced load-bearing capacity, while MoS₂ facilitated a reduction in friction due to its layered structure, enabling easy shear along basal planes. Tensile testing, conducted as per ASTM E8 standards, revealed an optimal balance between tensile strength and ductility at specific reinforcement levels, attributed to synergistic interactions between SiC-induced strengthening and MoS₂-mediated friction reduction. However, excessive particle addition caused agglomeration, leading to stress concentrations and microstructural anomalies that diminished mechanical properties.

Hardness tests on the weld zone, performed using the Rockwell scale, indicated a peak hardness of 148.9 HRN at 8 wt% SiC and 4 wt% MoS₂, highlighting the critical role of reinforcement in enhancing surface resistance to deformation. This research underscores the interplay between microstructural evolution and tribological mechanisms, providing valuable insights for designing advanced materials with superior wear resistance and mechanical performance for aerospace and automotive applications.