Anti-oxidation and tribology properties of MPCVD DLC films

The work aims to study the anti-oxidation and tribology properties of the DLC films deposited by MPCVD method. By using a flat-top bell jar MPCVD device, DLC films were deposited on glass with different microwave power and gas pressure. Surface chemical structures were characterized by X-ray photoelectron spectroscopy (XPS) and Raman spectra. The surface morphologies were observed and analyzed by EFSEM and the friction coefficients were tested and researched by using conventional mechanical probes. Ratios of IO1s/IC1s and sp2/sp3 decreased with increasing of microwave power and increased with increasing of gas pressure. The anti-oxidation property was enhanced when the sp2/sp3 ratio decreased. The results of EFSEM showed that when microwave power was increased from 500 W to 700 W, the agglomeration appearance of the DLC film cluster could be limited and this was accompanied with decline of the friction coefficient. When the microwave power reached 900 W, the surface of the DLC film showed cracks and this made the friction coefficient increase. When the microwave power was 700 W and the gas pressure was 8.0 kPa, DLC film with lowest friction coefficient and good anti-oxidation could be deposited. The anti-oxidation property of DLC film made by MPCVD method is affected by the ratio of the sp2/sp3. The lower the ratio is, the better the anti-oxidation property is. Ratio of sp2/sp3 and the roughness of the DLC surface are both factors that obviously affect the friction coefficient. The lower ratio and the more flat surface lead to lower friction coefficient. © 2018 Chongqing Wujiu Periodicals Press. All rights reserved.