Mechanical and tribological properties of AA2024 reinforced Al₂O₃ and ZrO₂ hybrid composite

Abstract Hybrid Metal Matrix Composite (HMMC) alloys are a very attractive material for excellent mechanical and tribological performance, and their properties can be easily customized by varying reinforcement types and amounts. This research investigated the mechanical and tribological properties of an Aluminium Alloy (AA) 2024 reinforced with 2 wt% Al 2 O 3 and (2, 4, 6) wt% ZrO 2 hybrid composites. The presence and distribution of reinforcements in the stir-casted samples were confirmed by SEM, EDS, and elemental mapping. The tribological tests were conducted on a pin-on-disc under dry and wet conditions using Taguchi’s L 9 orthogonal array. The SAE 20w40 oil and SAE 20w40 oil mixed with TiO 2 nano additive are lubricants. The hardness and tensile strength increase linearly with the addition of a single and continue to increase with multiple reinforcements. The HMMC exhibits a maximum hardness and tensile strength of 107 BHN and 209.281 MPa, respectively. The experimental results show that the dry condition’s wear rate is much higher than that of the composites lubricated with SAE 20w40, especially SAE 20w40 with TiO 2 nano additive. Compared to the base material, AA2024 reinforced with 2 wt% of Al 2 O 3 and 6 wt% of ZrO 2 exhibited an enhanced wear resistance of 0.0002353 mm 3 /min and COF of 0.118 with nano lubricant which is 40% and 21% higher than base lubricant.