Tribological characterization of LM26/SiC/Ni.-Gr. Hybrid aluminium matrix composites (HAMCs) for high temperature applications

Abstract

In this study, tribological characteristics of the hybrid composite material LM26/ SiC / Ni.-Gr. were studied under different temperature conditions. The LM26 aluminum alloy was reinforced with silicon carbide (SiC) with various weight fractions (0%, 10% and 20%) by keeping nickel-coated graphite (Ni.-Gr.) constant at 2%. Using stir casting setup wear test samples were prepared. Pin on disk equipment was used to assess the tribological performance of both pure aluminum alloy and hybrid composites on the basis of wear loss and friction coefficient. Further, the plan order for performing trials was developed with design of experiments (DOE) and analysis of variance (ANOVA) tools. It was found that the composite's tribological and mechanical performance under high temperature sliding wear conditions was improved because of the hybridization of hard and soft reinforcements. Experimental results revealed that load and temperature primarily affect both pure aluminum alloys and hybrid composites performance. Also low wear loss and friction coefficient were obtained during high-temperature wear tests. The LM26 + 20% SiC + 2%Ni.-Gr.hybrid composite showed the highest improvement in tribological performance. Worn surface analysis using SEM technique showed that hybrid reinforcement significantly increases wear resistance in hybrid aluminum composites. These findings indicate that the proposed hybrid aluminum composites can be considered as an alternative material in which wear-resistant and high-strength components are of primary importance in the automotive industry.