Effect of abrasive particle size on friction and wear behaviour of HVOF sprayed WC-10Co-4Cr coating

Abstract

The objective of the present work is to investigate the effect of abrasive particle size on friction and abrasive wear performance of HVOF sprayed WC-10Co-4Cr coating. WC-10Co-4Cr coating was deposited by HVOF technique on 316 SS substrate. Friction coefficient and abrasive wear rates were measured with varying abrasive particle size, load and sliding speed. The microscopic observations, XRD and XPS analyses of worn surface were used to analyze friction and wear data. The increase in abrasive wear rate with an increase in load and abrasive particle size was attributed to the transition in wear mechanisms. The variation in friction coefficient with abrasive particle size as a function of load and sliding speed was due to change in the contribution of adhesion and abrasion, and varying degree of tribo oxidation. With increasing sliding speed abrasive wear rate and friction coefficient decreased, which was due to the dominance of oxidative wear. The prevalence of fracture dominated mechanical wear processes led to an increased coefficient of friction at higher load.