High temperature wear behavior of Al2219/n-B4C/MoS2 hybrid metal matrix composites

Abstract

Abstract In the present work, high temperature wear behaviour of Al2219 (base Alloy), Al2219+2%n-B4C (mono) and Al2219+2%n-B4C+2%MoS2 (hybrid) metal matrix composites were investigated at different temperature conditions. The Al2219/2%n-B4C and Al2219/2%n-B4C/2%MoS2 metal matrix nano composites have been prepared through liquid metallurgical (stir casting) technique and high temperature wear tests were conducted on a pin-on-disc wear testing machine. The obtained results indicated that temperature, load and sliding velocity mainly affects the wear of developed metal matrix composites. The specific wear rate of Al2219, Al2219/2%n-B4C composite increases at elevated temperature. As the temperature increases from 50 °C to100 °C in a step of 25 °C the wear rate gradually increases. However, the specific wear rate of Al2219/2%n-B4C/2%MoS2 hybrid composite decreases at higher temperature. It is due to the surface the oxide layer formation at higher temperature and also MoS2 particles (solid-lubrication) resisting the wear and improvement in thermal stability of Al2219/2%n-B4C/2%MoS2 hybrid composite. The SEM analysis results reveals that the Al2219 alloy and Al2219/2%n-B4C composite shows the widest and deepest wear tracks and for the Al2219+2%n-B4C+2%MoS2 composite, depth and width of wear tracks are much smaller at elevated temperature.