Microstructure and wear performance of electro-sprayed self-lubricating Ni3Al/Cr3C2-MoS2 composite films

Abstract

The purposes of this study are to provide a simple and rapid fabricating method for self-lubricating Ni3Al matrix composite films and to evaluate the tribological performance of the self-lubricating composite films. Self-lubricating Ni3Al matrix composite films containing a fixed MoS2 content and varied contents of reinforced phases Cr3C2 were fabricated by electro-spraying. The phase compositions and the microstructures of the composite films were evaluated, and the effects of the Cr3C2 content on the mechanical and tribological properties under dry sliding conditions were investigated. Findings from the study showed that the addition of 10 wt% Cr3C2 to the composite films results in a more compact structure. A 10 wt% Cr3C2 content increases the hardness and the elastic modulus of the composite films, whereas it decreased with a Cr3C2 content higher than 10 wt%. Composite films with 10 wt% Cr3C2 showed the lowest friction coefficient of ~0.24, estimations of the underlying wear rates revealed a reduction of the resulting wear rate by the order of magnitude. This is an indication that the optimal Cr3C2 content for the enhancement of the wear-resistance property of the composite films is 10 wt%, and the potential tribological property was attributed to the balance and synergy between the lubricating and reinforced phases.