Improving the friction and wear characteristics of AZ31 alloy with the addition of Al2O3 nanoparticles

Abstract

The objective of the current study is to understand the effect of Al2O3 nanoparticle addition on the dry sliding wear behaviour of unreinforced AZ31 alloy. The nanocomposites with different Al2O3 (0.66, 1.11 and 1.5 wt%) were fabricated using powder metallurgy coupled with microwave sintering technique and secondary processed by hot extrusion. Using a pin-on-disc test rig dry sliding wear test was conducted at different loads (5, 7 and 10 N), sliding velocities (0.6, 0.9 and 1.2 m s−1) and sliding distance (500, 1000 and 1600 m). Worn surface analysis was carried out using a scanning electron microscope in order to study the wear mechanisms operating in the nanocomposites. Wear rate of all nanocomposites were found to increase with the increase in applied load and sliding velocity. AZ31 nanocomposite with 1.5 wt% Al2O3 showed the highest wear resistance at higher loads when compared to 0.66 and 1.11 wt% Al2O3 addition, respectively. Coefficient of friction was found to decrease with the increase in load while other parameters like sliding velocity and sliding distance had minimal effect. The predominant wear mechanisms operating in all nanocomposites were abrasive wear and delamination whose severity increased with the increase in applied load.