Effect of Speed on the Tribological Behavior of Fe–Cu–C Based Self Lubricating Composite

Abstract

In this work, the effect of different speeds on the tribological properties of sintered iron–copper–graphite (Fe–Cu–C) based self lubricating composites have been studied. Fe–Cu–C based self-lubricating composites were prepared by powder metallurgical compaction and sintering method. CaF2, a solid lubricant in weight percentages of 0, 3, 6, 9 and 12 was added to the base matrix consisting of Fe-2Cu-0.8C. The fabricated samples were tested for friction and wear at a constant load of 10 N and three different speeds of 0.5, 5 and 10 m/s. The surface properties of unworn and worn surfaces were analyzed using optical and scanning electron microscope. The friction and wear test of the composites exhibited decrease in coefficient of friction and increase in wear loss with the increase in speed. The results also revealed different trends in the friction behavior of the developed composites at low (0.5 m/s) and high speeds(5 and 10 m/s). However, at all test speeds, COF of samples with 3, 6 and 9 wt.% was less than the base matrix, and wear loss of 3 wt.% CaF2 sample was the lowest at all speeds. Ploughing, adhesive and delamination wear were the dominant wear mechanism as revealed by SEM. Based upon the findings, the developed material could be used for low and high speed antifriction applications.