Tribology in Industry (Mar 2014)
Effect of Ageing on Dry Sliding Wear Behaviour of Al-MMC for Disc Brake
Abstract
The present investigation shows the wear behaviour of as-cast and heat treated, A356 aluminium alloy reinforced with SiC and Graphite particles subjected to different ageing durations. The liquid metallurgy technique was used to fabricate the composites. The reinforcement content was varied from 0 to 9 % by weight in steps of 3 % of SiCp and fixed quantity of 3 % by weight of graphite particles. The castings were machined to ASTM standard and T6 heat treatment was carried out at 540 0C ± 5 for 12 hrs and quenched at 60 0C in water. All the specimens were artificially aged at different durations of 3, 6, 9 and 12 hrs at a temperature of 155 0C ± 5. The wear tests were performed for alloy and composites by varying load, speed and sliding distance for both aged and as-cast conditions by using a pin on disc wear testing machine. The results reveal that the wear rate of composites was less than that of non-reinforced alloy. It was found that the wear resistances of A356-9 SiCp-3 Gr composites aged at 9 hrs showed better wear resistance compared with other samples. However in both aged and as-cast materials, the wear rate was increased with the increase in load, speed and sliding distance. The tested samples were examined and analyzed using Scanning Electron Microscope (SEM) and X-ray energy-dispersive spectrometry (EDX).
