investigating the abrasive wear resistance of thermal-sprayed wcbased coatings

The purpose of this research was to investigate the abrasive wear behavior of wc–nimocrfeco (wc-n) and wc–fecral (wc-f) coatings deposited by high-velocity oxygen fuel (hvof) spraying. the abrasive wear resistance was evaluated by a dry sand rubber wheel (dsrw) test rig using abrasives silica 70 and alumina 60, and the values were then compared to those of conventional wc-co (wc-c) coatings. the abrasive wear with silica 70 indicated the “soft abrasion” regime, while alumina 60 abrasive caused a “hard abrasion” for all coatings. moreover, the wear rate of the coatings abraded by alumina 60 was around 1.2-7.8 times greater than that of silica 70. wc-f exhibited the greatest wear resistance compared to other coatings tested by silica 70 due to its lower mean free path and higher hardness compared to other coatings. wc-c coating revealed the cobalt matrix removal followed by wc fracture and pullout using abrasive silica 70, while wc-f and wc-n coatings represented a combination of subsurface cracking, wc pullout, and fracture. abraded by alumina 60, wc-c, wc-f, and wc-n coatings showed the evidence of grooving, pitting, and cutting. moreover, wc-c coating had the highest wear resistance due to its high fracture toughness and low porosity, protecting wc-c coating against severe cracking and grooving, respectively. cross-sectional images of the wear scars revealed a significant sub-surface cracking for wc-f and wc-n coatings while no significant cracking could be detected for wc-c coating.