Study of Varying Weight%, Particle Size and Artificial Aging of Al2O3 on the Hardness and Wear Resistance of Al 6082 Alloy Composites by Stir Casting

In this study, the effect of artificial aging, particle size, different weight fractions (1, 1.5, 2, and 2.5%) of Al2O3 on the hardness and wear resistance of Al 6082 alloy composite produced by stir casting method is studied. Al 6082 alloy composite specimens strengthened individually with Al2O3 particles of 45 μm and 40–50 nm were produced by stir casting method. The composite specimens were first solutionized followed by artificial aging at 180 °C for various time periods (1, 2, 4, 6, 8, 10, 12, 14, 16, 18 and 20 h). The hardness and wear tests were performed on the heat-treated and non-heat-treated specimens. Vickers microhardness tests demonstrated a tremendous improvement in the composites’ VHN values due to artificial aging and the addition of varying wt% of micron/nano-sized Al2O3 reinforcement. The T6-treated Al 6082 alloy composite specimens reinforced with nano-Al2O3 particles showed an enhancement in VHN microhardness and wear resistance when compared to the pure Al 6082 alloy and composite specimens reinforced with micron-sized Al2O3 reinforcement. Pin-on-disc wear testing demonstrated that T6 specimens reinforced with nano-Al2O3 exhibited enhanced wear resistance than the composite specimens reinforced with micron-sized ceramic reinforcement. Worn surface morphology was carried out using FESEM to study the mode of wear.