| TiN as the first industrial hard film has grown over the forty years, and still active in all aspects of the industrial protection fields. TiN films have many superior performances, such as high hardness, good toughness, high adhesion strength, low resistivity, wear and corrosion resisting. And the deposition process conform the idea of the green manufacturing industry, so TiN film in the functional and application areas are still have a big space for improvement.With the development of the social and industry, people are getting more and more about the performances of the films. And according to different demands developed thin film with special properties. But the TiN due to its own defects, limited its application in some fields,such as columnar crystal structure, and more than 500 ℃ easily oxidized. Deposited Ti/TiN multilayer film can inhibit the growth of TiN columnar crystal structure, and improve the hardness, toughness, adhesion strength, mechanical properties, wear-resistant and corrosion properties of the TiN monolayer film. In this paper, changed the deposition time of Ti layer and TiN layer by multi arc ion plating, Ti/TiN multilayer films with different modulation ratio were prepared. And contrast to TiN monolayer film, the mechanical properties, wear-resistant and electrochemical properties of Ti/TiN multilayer films with different modulation ratio were investigated. The results showed that:(1) The Ti/TiN structure density, and no obviously defects. Ti/TiN multilayer films contain Ti and TiN phases, and TiN phase with(111) preferred orientation. The roughness of multilayer films were decreased, and the surface was more smoother. The sample S3-1:3 has the lowest roughness of 19 nm. With the increase of the thickness of TiN layer, the sample S5-1:7 has the highest hardness of 24.4 GPa. But S3-1:3 and S4-1:5 have higher hardness/elastic modulus ratio(H/E). It shows that they have excellent anti damage ability and elastic deformation ability. In the testing of adhesion strength, compared to TiN monolayer film, four groups of Ti/TiN multilayer film samples showed higher adhesion strength, and the critical load are more than 25N. The multilayer film samples S3-1:3 and S4-1:5 showed excellent mechanical properties.(2) Under the 5N load, the friction coefficient of TiN monolayer film is the highest,which was 0.59. The friction coefficient of Ti/TiN multilayer films are lower than TiN monolayer film, because of soft Ti layer anti-shearing effects, and hard TiN layer load-bearing effects. Thus reduced the friction coefficient and wear rate. And sample S3-1:3 have the lowest friction coefficient and wear rate, which were 0.40 and 1.25×10-7 mm3/(N·m)respectively. Compared to the TiN monolayer film and the other Ti/TiN multilayer films, the wear rate is reduced by an order of magnitude. Under 7 N load, sample S3-1:3 have the lowest friction coefficient and wear rate, which were 0.29 and 3.49×10-6 mm3/(N·m) respectively.The wear of TiN film and Ti/TiN multilayer films are mainly dominated by abrasive wear and adhesive wear, respectively.(3) In the deionized water, the corrosion current density of the multilayer films are lower than the TiN monolayer film. Which shows that the corrosion reaction rate are lower than TiN film. In 3.5 % NaCl solution, the corrosion current density of multilayer films S2-1:1, S3-1:3and S4-1:5 are lower than TiN film by an order of magnitude, corrosion potential of S3-1:3and S4-1:5 increased by 67 mV and 48 mV respectively. And multilayer film S3-1:3 has the best corrosion resistance. After 720 h salt spray, the samples surface have corrosion phenomenon. Then corrosion resistance testing were carried out in the 3.5 % NaCl solution.Comparison of five groups of samples, the corrosion resistance have decreased, and multilayer sample of S3-1:3 showed better corrosion resistance than the other samples. |
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