nc-Ti C/a-C:H nanocomposite films were prepared by filtered cathodic arc technique. The influence of C_2H_2/Ar flow ratio on the composition, structure, and mechanical properties of films was investigated by X-ray ph...nc-Ti C/a-C:H nanocomposite films were prepared by filtered cathodic arc technique. The influence of C_2H_2/Ar flow ratio on the composition, structure, and mechanical properties of films was investigated by X-ray photoelectron spectroscopy(XPS), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR),Raman spectroscopy, nanoindentation, and ball-on-disc tribometry. The films show a nanocomposite structure in which Ti C crystallites are embedded in the amorphous matrix of a-C:H phase. C content in films increases with the flow ratio of C_2H_2/Ar, simultaneously, the crystallite size of TiC decreases. Contrary to the nc-Ti C/a-C:H films deposited by magnetron sputtering in which the sp3 C content increases with C_2H_2 flow rate, the increase of C_2H_2 flow rate leads to the increase of sp2 C content in films deposited by filtered cathodic arc technique. The nc-Ti C/a-C:H films deposited by cathodic arc technique have a pronounced hardness maximum of 30 GPa under the C_2H_2/Ar flow ratio of 12. Tribological performance of films is controlled by the sp2 content in films. Higher sp2 content promotes the formation of graphite-like transfer layer during sliding,and results in lower wear rate and friction coefficient.展开更多
基金financially supported by the Ministry of Science and Technology of China(973 Plan)(No2013CB632303)the National Natural Science Foundation of China(Nos.51001084 and 51275154)
文摘nc-Ti C/a-C:H nanocomposite films were prepared by filtered cathodic arc technique. The influence of C_2H_2/Ar flow ratio on the composition, structure, and mechanical properties of films was investigated by X-ray photoelectron spectroscopy(XPS), X-ray diffraction(XRD), Fourier transform infrared spectroscopy(FTIR),Raman spectroscopy, nanoindentation, and ball-on-disc tribometry. The films show a nanocomposite structure in which Ti C crystallites are embedded in the amorphous matrix of a-C:H phase. C content in films increases with the flow ratio of C_2H_2/Ar, simultaneously, the crystallite size of TiC decreases. Contrary to the nc-Ti C/a-C:H films deposited by magnetron sputtering in which the sp3 C content increases with C_2H_2 flow rate, the increase of C_2H_2 flow rate leads to the increase of sp2 C content in films deposited by filtered cathodic arc technique. The nc-Ti C/a-C:H films deposited by cathodic arc technique have a pronounced hardness maximum of 30 GPa under the C_2H_2/Ar flow ratio of 12. Tribological performance of films is controlled by the sp2 content in films. Higher sp2 content promotes the formation of graphite-like transfer layer during sliding,and results in lower wear rate and friction coefficient.