Comprehensive investigation of microstructure, hardness, and wear behavior in aluminum matrix composite reinforced with TiO ₂ and WC

This study presents a comprehensive investigation of the microstructural characteristics, hardness, and tribological physical characteristics of Aluminum (Al) AA6063 alloy matrix composites strengthened with Titanium Dioxide (TiO 2 ) and Tungsten Carbide (WC) particles. The mono and hybrid Metal Matrix Composites (MMCs) were manufactured via the stir casting manner with 5 wt.% TiO 2 and varying wt.% of WC (0% to 1.0%) to study the influence of reinforcement on material properties. The T6 thermal treatment was performed on the MMCs with different ageing temperatures (145 °C, 165 °C, and 185 °C). Vickers hardness testing demonstrated improved hardness with increasing particles, and 165 °C aged hybrid MMC showed higher hardness, which is 37% higher than the as-cast hybrid MMC hardness. The microstructural exploration using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS) publicized an even dissemination of reinforcement phases inside the Al matrix. X-ray Diffraction (XRD) observed the occurrence of Al, TiO 2 , and WC particles. The tribological behavior was evaluated through pin-on-disc testing, showing a reduced Specific Wear Rate (SWR) with higher reinforcement content, and sliding wear impacting wear variables were optimized through the Taguchi technique. The lower load condition showed a mild SWR with an abrasive wear mechanism, highlighting the MMC's potential for wear-resistant applications.