| In this study, TixAly-TiN composite coatings with excellent performance were produced successfully on titanium alloy by using laser gas nitriding and synchronous feeding power technology. Then the microstructure, phase composition and microhardness of TixAly-TiN composite coatings synthesized at different laser powers in laser nitriding were investigated. Finally, the research was mainly focused on the wear resistance, the erosion resistance and the oxidation resistance of TixAly-TiN composite coatings. The main conclusions are as follows:(1) The crack-free and pore-free TixAly-TiN composite coatings were produced successfully on titanium alloy through the proposed method. A good metallurgical combination between matrix and composite coatings formed.(2) The crystalline phases of TixAly-TiN composite coatings consist mainly of TixAly intermetallic phase and TiN reinforced phase. By comparing with the TC4 alloy substrate, the TixAly-TiN composite coatings exhibited higher microhardness, which was dependent of volume fraction and distribution of TiN reinforced phase.(3) The sliding wear resistance and oxidation resistance of TC4 alloy were significantly improved through synthesizing TixAly-TiN composite coatings on its surface, the erosion resistance of TC4 alloy except. The improvement of sliding wear resistance was dependent of TiN reinforced phase; the improvement of oxidation resistance was dependent of the Al element to add; while the low fracture toughness of TixAly-TiN composite coatings led to the poor erosion resistance. |
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