Graphite-like amorphous carbon film was fabricated by unbalanced magnetron sputtering technique.Raman spectroscopy,atomic force microscopy(AFM)and tribometer were subsequently used to investigate the microstructure and tribological properties of the resultant film.It is found that the deposited carbon film is dominated by sp 2 sites,and the intensity ratio of the D and G peaks is as high as 4.0,which is one order of magnitude larger than that of diamond-like carbon films with high sp 3 content,indicating a more graphite-like structure.However,the as-deposited carbon film exhibits moderately high hardness(13.7 GPa),low internal stress(0.38 GPa)and superior tribological properties with high load bearing capacity(Hertz contact stress about 3.2 GPa)and low wear rate(2.73×10-10 cm3/N.m)in ambient atmosphere.Although it displays a poor wear resistance in water lubricated condition,a superior wear resistance is achieved in oil lubricated condition.Its inherent physical property,the formation of transfer layer and the friction induced chemical reactions may be commonly responsible for its tribological properties.
Wang YongjunLi HongxuanJi LiZhao FeiLiu XiaohongWu YanxiaZhou HuidiChen Jianmin
Amorphous hydrogenated carbon(a-C:H)and Ti-incorporated a-C:H(Ti/a-C:H)films were deposited by magnetron sputtering with a mixture gas of CH4 and Ar.The effect of the Ti incorporation on the chemical composition,microstructure and properties of the as-deposited and the annealed films were investigated by various techniques.It has been shown that the bonding structure and the internal stress were sensitive to the incorporation of the Ti atoms.The results of the XPS revealed that the concentration of Ti atom on the surface of the film increased when the Ti/a-C:H film annealed at 300oC.The tribologcial properties of the(Ti/)a-C:H films changed greatly after annealed,due to the graphitization,oxidation of carbon,and so forth.It compared and discussed in detail the change of the microstructure and properties of the a-C:H and Ti/a-C:H films before and after
Wang YongxiaYe YinpingLi HongxuanJi LiWang YongjunWu YanxiaLiu XiaohongChen JianminZhou Huidi