研究論文
Effect of Plasma Treatment on Friction Coefficient of Diamond-like Carbon Films
2014 年 65 巻 12 号 p. 621-624
詳細
2014 年 65 巻 12 号 p. 621-624
In this study, diamond-like carbon(DLC)films are modified using O2 and CF4 plasma generates by radio frequency(RF), taking into account surface wetting and tribological properties. Surface properties of O2 and CF4 plasma-treated DLC are characterized using atomic force microscopy(AFM), Attenuated total reflectance-Fourier transform infrared(ATR-FTIR)spectroscopy, ball-on-disk friction testing, and contact angle measurements. The results indicate that hydroxyl group generates on the surface of the O2 plasma-treated DLC with surface roughness of approximately 0.20-0.25 nm, while fluorinated group also generates on the surface of the CF4 plasma-treated DLC with surface roughness of approximately 0.16-0.21 nm. The O2 plasma-treated DLC films present hydrophilic surfaces due to their low contact angles and high surface energies. In contrast, CF4 plasma-treated DLC show hydrophobic surfaces, as evidence by their high contact angles and low surface energies. Further, CF4 plasma-treated DLC film surfaces exhibit friction coefficients as low as untreated DLC, but O2 plasma-treated DLC exhibit higher friction coefficients than that of the untreated DLC. It is concluded that CF4 plasma treatment can be used to produce hydrophobic DLC, making DLC a favorable non-wetting surface and improving its friction coefficient.
