MPCVD类金刚石膜抗氧化和摩擦性能的研究

目的研究MPCVD法制备的DLC膜的抗氧化和摩擦性能。方法使用石英钟罩式MPCVD装置,在CH4-H2体系中,通过不同微波功率和沉积气压的正交实验,在载玻片上沉积DLC膜。通过X射线光电子能谱和拉曼光谱对DLC膜表面的化学组成进行测试分析,采用场发射扫描电镜对DLC膜的表面形貌进行观察分析,采用摩擦磨损仪对DLC膜的摩擦性能进行测试研究。结果同一沉积气压下,IO1s/IC1s和sp2/sp3的比值随着微波功率的上升而下降;同一微波功率下,IO1s/IC1s和sp2/sp3的比值随着沉积气压的上升而上升。DLC膜的抗氧化性能随着sp2/sp3比值的下降而上升。场发射扫描电镜结果表明,微波功率由500 W上升至700 W时,DLC膜表面的团聚现象明显受到抑制,摩擦系数下降。当微波功率上升至900 W时,DLC膜表面出现明显裂痕,摩擦系数上升。微波功率为700 W、沉积气压为8.0 k Pa时,可得到氧化性能较好、摩擦系数最低为0.14的DLC膜。结论 MPCVD法制备的DLC膜的抗氧化性能受sp2/sp3比值的影响,比值越低,抗氧化性能越好。摩擦性能同时受sp2/sp3比值和其表面粗糙度的影响,比值越小,表面越平整,摩擦系数越小。

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.