Tribocorrosion behaviors and mechanisms of in-situ TiC/TiB/Cr2B reinforced CrMnFeCoNi high-entropy alloy composite coatings prepared by laser cladding

Tribocorrosion has long been a challenge in the field of marine protection. To address this challenge, this study used laser cladding in-situ synthesis to fabricate CrMnFeCoNi high-entropy alloy composite coatings containing multiple ceramic reinforcement phases. By analyzing the microstructure, microhardness, electrochemical properties, and tribocorrosion performance of the cladding layer, the effects of different B₄C and Ti mixture additions (10 %, 20 %, and 30 %) on the high-entropy alloy composite coatings were studied. The results show that the synergistic effect of carbides and borides significantly enhances the passivation ability of the composite material's surface. The C20 coating with a 20 % mixture addition exhibited the best corrosion resistance. The precipitation of TiC particles not only suppressed dislocation motion but also effectively blocked corrosion pathways. When the mixture addition reached 30 %, the C30 coating achieved the highest microhardness of 380.35 HV_0.2, demonstrating the optimal tribocorrosion resistance. This study provides both theoretical and practical guidance for the service performance of high-entropy alloy composite coatings under coupled tribocorrosion conditions in harsh marine environments.