Structure and tribocorrosion behavior of Ti/TiN multilayer coatings in simulated body fluid by arc ion plating

The TiN coating and Ti/TiN multilayer coatings were successfully fabricated on Ti6Al4V alloy by multi-arc ion plating. The Ti/TiN multilayer coatings with a total thickness of 4.6 μm and the TiN coating were prepared with a thickness of 5.6 μm. The XRD results indicate that the TiN phase of Ti/TiN multilayer coatings has a face-centered cubic crystal with the strong preferred orientation of (111) while the TiN coating has the face-centered cubic crystal structure with a preferred orientation of (200). For TiN coating, the hardness is (27.5 ± 1.9) GPa, the load-bearing capacity is (19.0 ± 3.6) N. For Ti/TiN multilayer coating, the hardness is (26.8 ± 1.7) GPa and the load-bearing capacity is (60.4 ± 4.0) N. The Ti/TiN multilayer coatings have excellent tribocorrosion resistance and lower coefficient of friction in simulated body fluid at 37 °C, compared with Ti6Al4V alloy and TiN coating, the tribocorrosion resistance of the multilayer coatings increased by approximately 58 and two times, respectively. The material loss which arises from tribocorrosion is not simply the summation of pure corrosion and pure wear loss, the synergism between corrosion and wear takes a large proportion of the total volume loss. •TiN coating and Ti/TiN multilayer coatings were deposited on Ti6Al4V alloys by multi-arc ion plating.•Ti/TiN multilayer coatings exhibit excellent mechanical properties.•Ti/TiN multilayer coatings exhibit excellent tribocorrosion resistance in simulated body fluid.•The evolution of the microstructure of the multilayer coatings was studied.•The mechanisms of the multilayer coatings to improve the tribocorrosion resistance were explored.