Tribological Properties And Application Of The Diamond-like Carbon Films

Middle-frequency magnetron sputtering and plasma enhanced chemical vapor deposition techniques were used to deposit the diamond-like carbon films on silicon wafer and different metal surface. The effects of various process parameters on the microstructure and properties of the films were investigated systematically. The tribological behaviors of the films under different conditions were studied and possible tribological mechanisms were proposed. The main conclusions of the thesis were drawn as follows:(1) Ni-doped diamond-like carbon films were deposited on silicon wafer by middle-frequency magnetron sputtering with different Ni content. The effect of Ni content on microstructure and properties of the films were studied systematically. The result showed that with the Ni doped, the stress was decreased and the adhesion was increased. The excellent tribological properties could be obtained at a low Ni content.(2) Diamond-like carbon films were deposited on316L substrate by plasma enhanced chemical vapor deposition techniques. The influences of the precursor gases and working pressure on the microstructure, mechanical properties and tribological properties of the films were studied systematically. The result showed that the excellent properties could be obtained at a CH4/H2of20:10, the hardness about25GPa and the friction coefficient about0.044. When the working pressure of15Pa, the film hardness was as high as18.4GPa and showed the excellent mechanical properties. The film exhibited the low friction coefficient of0.035and excellent tribological properties at the working pressure of31Pa.(3) Diamond-like carbon films were deposited on316L substrate by plasma enhanced chemical vapor deposition techniques. The tribological properties of the films were investigated systematically under different conditions. The result showed that with the increase of load, the friction coefficient of the films was decreased in air, increased in water and increased firstly then decreased in diesel. With the increase of sliding speed, the friction coefficient of the films was decreased under different conditions, and the friction coefficient in diesel was lower than in water.(4) Diamond-like carbon films were deposited on Ti6AlV4and316L substrate by plasma enhanced chemical vapor deposition techniques. The tribological properties of the films were investigated systematically under different lubrication conditions. It’s shown that the excellent properties of the film could be obtained prepared on316L substrate. The effect of the substrate on the microstructure and properties was obvious. The research result indicated that the chemical process of fluid lubrication was an important parameter and needed to be considered. The lower friction coefficient and wear were obtained when the film contacted with synthetic oil.