Study of the Ti-20 wt. % Mo Composite Coating Prepared by Laser Cladding

Laser surface cladding was applied on low carbon steel to improve its surface properties. Mixed Mo and Ti powders with a Ti-to-Mo mass ratio of 4:1 were put onto the low carbon steel and subsequently treated by laser beam. The microstructure and composition modifications in the surface layer were carefully investigated by using SEM, EDX and XRD, respectively. A Ti-Mo intermetallic compound layer with thickness of similar to 300 μm was formed on low carbon steel. The bonding between the coating layer and substrate is good and the diffusion occurs in the interface between them. From the results it is very clear that the phases in the composites coatings are composed of β-Ti phase and Fe2Ti phases. The micro hardness of the coating reaches to above HV0.5 900. The improvement of the hardness of the coating on low carbon steel has been realized. Preliminary electrochemical studies have indicated Ti-Mo exhibits excellent corrosion resistance in 0.5 M NaCl solution.