Bonding and sliding wear behaviors of the plasma sprayed NiCrBSi coatings

Three NiCrBSi coatings with different hardness were deposited on 1045 steel by Atmospheric Plasma Spraying (APS). The cohesion bond strength of the coatings was characterized by scratch testing on coatings cross-sections. The tribological behaviors of the coatings, with a steel ball counterpart, were studied on a ball on disc tribotester under oil lubrication. The correlation between the wear behaviors and coating cohesion, as well as the wear mechanism and scratch mechanism of the coatings were discussed based on the microhardness measurement, microstructure observation, worn/scratch track surface analysis and determination of residual stress of the coatings.