Assessment of wear performance of flame sprayed and fused Ni-based coatings

Abstract

Characterization of the flame sprayed and furnace fused NiCrBSiC alloy coatings with two different carbon contents and 15–45 wt.% WCCo addition is described in terms of microstructure, microhardness and differential thermal analysis. Microstructural development of these coatings before and after fusing treatment is discussed to identify the precipitates in the coatings. Optimum fusing conditions (time and temperature) for wear-testing sample were investigated in terms of microhardness and porosity of the coatings. Wear performance of these coatings was also investigated by two- and three-body abrasive and dry sliding wear experiments. The coating of 35% WC with NiCrBSiC is showing the best quality (the highest hardness and the lowest porosity). However, 25% WC addition is showing the best wear resistance for Sugaru abrasive wear test, while 40% WC addition is showing the best wear resistance for DSRW (dry sand rubber wheel) abrasive wear test. It is also shown that the dry sliding wear resistance of the 20% (and/or 30%) WCNiCrBSiC composite coating is almost 10 times better than that of the quenched and tempered JIS SUJ2 bearing steel.