Mechanical properties of TiN ceramic coating on a heat treated Ti-13Zr-13Nb alloy
In this paper, mechanical properties of TiN coatings deposited on Ti–13Zr–13Nb alloys prepared by filtered arc deposition were analyzed. The influences of different heat treatment on the abrasion resistance of the substrate were studied, with regards to the coating properties, microstructural features, mechanical properties and the deformation mechanism using wear test and depth-sensing nano-indentation. According to the analysis, the microstructure and enhanced mechanical properties of the alloy substrate play a vital part in affecting the tribological properties of coatings. Parallel scars with patches of surface deformation in TiN coatings on air cooled and water quenched specimens after tribological test are obviously different from those of furnace cooled and aged water―quenched samples. Transformation of β phase into α” phase was triggered by the aging heat treatment, and it was found to be the inducement resulting in the increase of hardness in the substrate. The results show that the aging of the substrate can effectually inhibit the fault activities of the TiN coating and improve the absorption of deformation energy at the surface of the sample, which enhances the coating ductility.