| Titanium nitride films are deposited on 9Cr18 stainless steels by multi-arc ion plating with linear magnetic-filter. The effects of magnetic filtration are investigated for the surface morphology, material structure and mechanical properties of TiN films. Their tribological performance were evaluated systematically under vacuum environment when composite lubricating system was composed of TiN films and various liquid lubricants. Furthermore, the influence of textured TiN films are studied on the tribological properties of solid film-oil composite lubricating system. The main research achievement in this thesis are as follows:(1) With applying linear magnetic filtration, to some extent, It can filter macro-particle effectively and reduce the growth defects of TiN films during deposited process. Compared with multi-arc ion plating, TiN films deposited with linear magnetic filter units possess smaller grain, more compact structure, lower porosity, more smooth surface, stronger adhesion force and higher hardness. Both ion bombardment and grain refinement are main factors to improve the mechanical properties of TiN films.(2) Compared with the tribological performance of steel/steel friction pairs lubricated with oil under vacuum environment, TiN/oil composite lubricating systems show excellent lubrication properties under same experiment conditions. The composite lubricating systems possess lower friction coefficient, less wear ratio. Between the four types of lubricating systems, TiN/silicone oil composite system shows worse anti-wear properties, and the others containing TiN/PFPE, TiN/MACs, TiN/P201 composite systems present better lubrication properties. TiN/P201 lubricating system shows the least anti-wear ratio. The tribological mechanism of composite lubricating systems is the adhesive wear and abrasive wear. The main factors which affect the tribological properties of composite lubricating systems are wettability, kinematic viscosity and the natural lubrication properties of liquid lubricants and the centrifugal force generated during the sliding process of ball-disk tests.(3) The textured TiN films with micro-dimples in the film surface were prepared by electrolytic treatment. The diameter and morphology of dimples in the TiN film surface can change through controlling electrolytic voltage and current, test time, electrolyte concentration to achieve the controllable preparation of textured TiN films. The different lubrication properties of textured TiN films are investigated under various lubricating oil. The dimple diameter plays a important role on the lubrication properties of the textured TiN films, which not only reduces the friction coefficient, but protracts the wear life of friction pairs. |
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