Interfacial and tribological properties of laser deposited TiOxNy/Ti composite coating on Ti alloy

Abstract In this work, a wear-resistant TiOxNy/α-Ti composite coating was deposited by laser cladding TiO2 powder onto Ti-6Al-4V in air. Dendritic TiOxNy reinforcements were synthesized in situ via reactions between Ti, TiO2 and N2. The partially-melted substrate mixed with the ceramic melt and formed α-Ti matrix that bonded chemically with the reinforcements. Stacking faults, induced by thermal stress, were found in the TiOxNy grains, which exerted a strain hardening effect. The coating had an average microhardness of 1417 HV0.3, four times that of Ti-6Al-4V. The wear resistance of the composite coating was 3.7 times that of Ti-6Al-4V, which was attributed to its high hardness and the strong TiOxNy/α-Ti and coating/substrate interfaces.