Enhanced mechanical properties and corrosion resistance of remanufactured Ti-6Al-4V alloys by combining laser cladding and boriding post-treatment processes

In this study, Ti boride ceramic coatings were prepared on TC4 coating surfaces using boriding post-treatment. The effects of different holding times on the microstructural evolution, mechanical properties and corrosion resistance of laser cladding coatings were investigated. The results showed that the hardness of the coatings was affected by the phase content in various regions of the coatings. The volume fraction of martensite in the coating was significantly reduced after boriding process. The boriding process produced TiB whiskers and a boride layer on the surface of the coating, with a maximum hardness of 1,185 Hv, and the corrosion resistance of the boride layer decreased and then increased with the extension of the holding time. After 10 h of holding, the borides produced on surface were microporous and accelerating corrosion. The density of the boride layer increased after 20 h of holding, and the corrosion resistance was significantly increased.