Friction and wear behaviour of Fe-Cu-C based self lubricating material with CaF2 as solid lubricant

Abstract

Purpose This paper aims to investigate the effect of CaF2 (calcium fluoride) addition as a solid lubricant on the friction and wear behaviour of sintered Fe-Cu-C materials under different loads. Design/methodology/approach In this study, the effects of CaF2 added in varying weight percentages on the friction-wear properties of Fe-2Cu-0.8C alloys are investigated. Five Fe-2Cu-0.8C-based compositions comprising CaF2 in 0, 3, 6, 9 and 12 Wt.% were prepared using the single-stage compaction and sintering technique. Friction coefficient, wear loss, hardness and compressive strength of the specimens were measured. The worn-out surfaces were analysed using a scanning electron microscope. Friction and wear tests were carried out on pin-on-disc machine under dry sliding conditions at room temperature. Findings The alloy with 3 Wt.% CaF2 was found to be useful in improving wear and friction properties, whereas higher contents of CaF2 resulted in increased wear and friction. Apart from enhanced tribological properties, a slight decrease in the compressive strength was also observed in the 3-Wt.%-CaF2-added sample. Adhesion and abrasion were the prominent wear types observed during this study. Originality/value A new self-lubricating composite is developed where CaF2 is used as a solid lubricant in a Fe-Cu-C-based matrix. CaF2, being a high-temperature lubricant, is tried and tested for friction and wear at room temperature, and the results show that the addition of CaF2 in Fe-Cu-C improved its friction and wear properties. Thus, the developed material can be used for antifriction applications.