Effect of different HVOF coatings on the tribological behavior of PVD/ HVOF duplex coatings

CrN film shows obvious differences in hardness, elastic modulus, and thermal expansion coefficient between film and substrate, suffering from poor adhesion and wear resistance. Here we combined PVD and HVOF technologies to produce CrN/WC-12Co and CrN/WC-10Co-4Cr coatings, and then compare their mechanical and tribological behavior with that of CrN film. We show that the PVD/HVOF coatings exhibit higher hardness, load carrying capability, and adhesion; the wear resistance also be improved greatly, especially for CrN/WC-10Co-4Cr. We discuss the wear mechanism of such duplex coatings and analyze the influence of different HVOF coatings on the deposition characteristic of CrN film.