Microstructure, Corrosion Resistance, and Wear Resistance of In Situ Synthesized NiTi-Based Coating by Laser Induction Hybrid Rapid Cladding

NiTi-based intermetallic compound coating was in situ synthesized on the surface of Ti6Al4V (TC4) substrate by laser induction hybrid rapid cladding. The microstructure, microhardness, corrosion resistance, and wear resistance of coating were systematic investigated. The results show that a good metallurgical bond exists between the coating and substrate. The coating mainly consists of NiTi, Ti 2 Ni, and Ni 3 Ti intermetallic compounds. The microhardness of coating is up to 650 HV, about 2.2 times than that of TC4 alloy. As uneven passivation film forms on the coating surface, a lot of pitting corrosion occurs, and thus, the corrosion resistance of coating decreases slightly compared to TC4 substrate. As dispersive intermetallic compounds exist, the coating possesses a better wear resistance, which is 1.7 times higher than that of TC4 alloy.