Effect of temperature on wear and friction behavior of as-cast and heat-treated LM25/SiC aluminum matrix composites

Abstract

Purpose The purpose of this paper is to evaluate the influence of temperature, load and sliding speed on wear and friction behavior of LM25/SiC composites in as-cast and heat-treated conditions. Design/methodology/approach The LM25/SiC aluminum matrix composites (AMCs) were prepared using the stir casting process. The wear tests were carried out using a pin-on-disc setup in dry condition. The three levels of each parameter, i.e. 100, 150 and 200°C operating temperature; 15, 25 and 35 N load; 0.8, 1.6 and 2.4 m/sec sliding speed, were considered for the investigation. ANOVA has been carried out to evaluate the percentage contribution of parameters. Scanning electron microscope analysis of worn surfaces has been carried out to understand the wear mechanism. Findings The wear and coefficient of friction (COF) increase with the increase in the temperature, load and sliding speed within a selected range for as-cast as well as heat-treated LM25/SiC AMCs. The mean values of wear and COF in heat-treated samples were found to be lower than as-cast samples for all cases. It was observed that the percentage wear increases significantly as temperature increases in as-cast AMCS. Mild to severe wear transition was observed at 150°C. In heat-treated AMCs, mild wear was observed irrespective of temperature. It was also observed that as the temperature increases, transition of wear mechanism from abrasive to adhesive (including delamination) occurs earlier in as-cast samples as compared to heat-treated samples. Originality/value There is a lack of data on combined effect of temperature, load and sliding speed on tribological aspects of as-cast and heat-treated LM25/SiC AMCs, limiting its applications. The present research work has addressed this gap.