Wear resistance of in situ synthesized titanium compound coatings produced by laser alloying technique

Ti–C and Ti–Si titanium compound coatings on a Ti–6Al–4V substrate are in situ synthesized by laser alloying technique to improve wear resistance of the titanium alloy. Microstructure and phase structure of the in situ synthesized coatings are investigated to understand behaviors of different kinds of titanium compound coatings. Compounds in the in situ synthesized Ti–C coating are mainly dendritic, and compounds in the in situ synthesized Ti–Si coating are block-like, lath-like and dendritic. The in situ synthesized Ti–C coating mainly contains TiC, and the in situ synthesized Ti–Si coating is chiefly composed of TiSi2 and Ti5Si3. Microhardness of the in situ synthesized Ti–Si coating and the in situ synthesized Ti–C coating is in a range of 1500–1000 HV0.1 and 1400–1100 HV0.1, respectively. Evaluation of wear resistance reveals that the in situ synthesized coatings improve the wear resistance of the Ti–6Al–4V alloy greatly. And the in situ synthesized Ti–Si coating displays better wear resistance than the in situ synthesized Ti–C coating.