Characteristics and bonding behavior of Stellite 6 alloy coating processed with supersonic laser deposition

This paper presents a study of Stellite 6 powder deposited on medium-carbon steel over a range of laser deposition temperature, with emphasis on investigating the role of laser irradiation in the supersonic laser deposition (SLD) process. The peak coating thickness and the microhardness of the coating specimens produced with different deposition temperatures are measured to investigate the influence of laser irradiation on the coating characteristics. The coating bonding behavior is assessed via the analysis of interfacial element diffusion and fractured surface morphology under three-point-bending test. The results show that increasing the deposition temperature can improve the deposition efficiency significantly and induce interfacial element diffusion, which implies that the introduction of laser heat into cold spray (CS) permits a change in the thermodynamic state of impacting particles and substrate, thereby provides good interface bonding at lower velocities as compared with the CS process. This research finds that SLD is capable of producing Stellite 6 hardfacing with combined mechanical and metallurgical bonding.