Wear Rate Behavior of As-cast and Heat Treated Hybrid Aluminum Metal Matrix Composites

Abstract

In the present study the effect of sliding speed on wear behaviour of as-cast and heat treated Aluminum alloy/composites has been investigated. Aluminum alloy series A356 is used as matrix, Silicon Carbide particles (SiCp) and graphite (Gr) particles are used as reinforcements. The proposed Aluminum Metal Matrix Composites (AMMCs) were fabricated by stir-casting. In the Aluminum A356 matrix, the reinforcement SiCp was varied from 0 to 9% by weights in steps of 3%, in addition to it 3% by weight Gr particles was also added. The castings were machined as per ASTM standard and T6-heat-treatment was carried out. Specimens were aged at different durations of 3, 6, 9, and 12hrs at a temperature of 155° C. The pin-on-disc wear testing machine was used to evaluate the wear rate of the composites. The results revealed that by increasing the reinforcement and ageing at T6-9hrs showed a maximum wear resistance in all the sliding tests. The reinforcements were restricted to 9% by weight due to the formation of agglomeration. The increase in sliding speed showed an increase of wear rate. The wear tested samples were examined for microstructure using scanning electron microscope (SEM) and the composition of worn out surface was confirmed using energy dispersive spectrum (EDS).