Comparative Analysis of Nano-powder Reinforcements on Tribological Properties of AA5754 Composites Fabricated via Friction Stir Processing

This study aimed to reveal the influence of different nanoceramic powder additions on the hardness and wear behavior of AA5754-based nanocomposites produced via friction stir processing (FSP). CNTs, SiO₂, and Al₂O₃ nano powders were incorporated into an AA5754 matrix using a blind-hole strategy and FSP with a triangular pin tool geometry. Single and double FSP passes were performed at a constant tool rotation speed of 1660 rpm and a traverse speed of 20 mm/min. The developed nanocomposites were characterized based on their microstructure, microhardness, and wear resistance. The results showed the successful incorporation and dispersion of the nano powders in the AA5754 matrix using a triangular pin geometry. Microhardness improved with all nano powder types, with the CNTs reinforcement showing the highest enhancement after both single-and double-pass FSP. Wear resistance was significantly improved in the nanocomposites, particularly with the addition of CNTs, which was attributed to the enhanced load-bearing capacity, improved thermal and mechanical properties, and solid lubrication mechanism provided by the CNTs. Roughness analysis of the worn surfaces revealed a more uniform wear behavior and reduced mean wear depth in the nanocomposites compared to the unreinforced alloy, with CNTs reinforcement exhibiting the most significant improvement, followed by Al₂O₃ and SiO₂. This study demonstrates the effectiveness of FSP in producing AA5754-based nanocomposites with enhanced hardness and wear resistance, highlighting the potential of CNTS reinforcement for superior tribological performance.