Tribiological behavior of WC- GR reinforced hybrid composites.

Abstract

In the present investigation the sliding wear behavior of as-cast and T6 heat treated Al6061 alloy and WC-Gr reinforced hybrid composites were studied for different applied loads. Using liquid metallurgy technique, composites were synthesized for 1 - 4 wt% of tungsten carbide (WC) in steps of 1 wt% and 4 wt% of graphite (Gr) reinforcement. The cast composites were solution heat treated at 500-550 0C and artificially aged for 1,3,5 hrs at 1750C. The results revealed that the strength and hardness of the composites improved significantly with heat treatment. The wear tests were conducted for different loads for a sliding distance of 3 km and sliding velocity of 2.62 m/s according to ASTM G-99 standard using pin-on-disc apparatus. The specific wear rate of heat treated composites gradually decreased with the increase in sliding distance and the maximum wear resistance was observed in 5 h aged Al6061-3wt%WC-4wt%Gr composites. The worn surfaces of the samples were studied under scanning electron microscope to understand the microscopic wear behavior.