MECHANICAL AND TRIBOLOGICAL PERFORMANCE OF AL7075 METAL MATRIX COMPOSITES REINFORCED WITH NANO Al₂O₃ PARTICLES: AN EXPERIMENTAL INVESTIGATION
Krishna Nandan, Mukesh Kumar
Department of Mechanical Engineering, Vivekananda Global University, Jaipur, India
Abstract: Nanostructured aluminum oxide (Al₂O₃) reinforced metal matrix composites (MMCs) based on Al7075 alloy have emerged as novel structural materials for applications requiring excellent mechanical properties and wear resistance. This research work explores the effect of nano Al₂O₃ reinforcement volume fraction (0-4 wt.%) on the mechanical and dry sliding wear characteristics of stir cast Al7075/Al₂O₃ MMCs. Yield and ultimate tensile strengths, percentage elongation and Vickers microhardness measurements were performed following standard procedures to develop a structure-property correlation. The mechanistic assessment revealed a gradual improvement in mechanical performance with increasing reinforcement content up to an optimum of 3 wt.% Al₂O₃. The microalloyed composite with 3 wt.% Al₂O₃ exhibited the highest yield and ultimate tensile strengths of 202.1 N/mm² Further increase in the reinforcement content, however, led to a slight decrease in mechanical properties, likely due to particle clustering and interfacial defects within the composite. The wear performance of the composite was evaluated in the pin-on-disc configuration over Wear rate studies illustrated that the composite containing 3 wt.% Al₂O₃ reinforcement showed the least rate of wear (2.3 × 10⁻3 mm³/m) at a 1 An increase in wear rate was observed with rising normal load and sliding distance, while moderately high sliding speed of 350 RPM resulted in the lowest wear rates for all compositions, indicating a shift in wear mechanism from abrasion to adhesion wear. This study demonstrates that 3 wt.% nano Al₂O₃ reinforcement is the optimal composition of Al7075-based MMCs for a combination of improved mechanical and tribological performance, with optimal properties for aerospace, automotive and structural engineering applications.
Keywords: Aluminium Metal Matrix Composite (Al-MMC), Nano Al₂O₃ Reinforcement, Mechanical Characterization, Dry Sliding Wear Behavior
VOLUME 10 ISSUE 04 2026: 172 – 202