金属密封环表面大气压等离子体枪沉积类金刚石薄膜耐磨性能

Wear-resistance of Diamond-like Carbon Thin Films Deposited on the Metal Seal Ring Surface by Plasma Gun at an Atmospheric Pressure

采用大气压介质阻挡放电等离子体枪,在低温下(<350℃),以甲烷为单体,氩气为工作气体,在金属密封环表面制备一层附着牢固的类金刚石薄膜(DLC),以期改善其表面耐磨性能。利用激光拉曼(Raman)光谱分析所制备DLC薄膜的结构;利用原子力显微镜(AFM)分析其表面形貌;利用划痕仪测量其与基体的结合力;用扫描电子显微镜(SEM)观察其划痕形貌;并利用球-盘摩擦磨损实验仪考察其耐磨性能。结果表明:在本实验工艺条件下沉积的类金刚石薄膜厚度约为500nm,薄膜均匀且致密,表面粗糙度为Ra5～6nm,其与基体结合力达到49N;制备的DLC薄膜具有优良的减摩性,其摩擦因数为0.148,较基体20CrNiMo的摩擦因数0.65明显减小,且耐磨性能得到提高。

At atmospheric pressure,Diamond-like Carbon（DLC）thin films were deposited on the metal seal ring surface by a dielectric barrier discharge（DBD）plasma gun at low temperature（350 ℃）,with CH4 as a precursor and Ar as dilution gas.The structure of the DLC thin film was analyzed by Laser Raman spectroscope.The surface morphology was observed through Atomic Force Microscope（AFM）.The adhesion between the DLC thin film and the substrate was investigated with the scribe testing.The morphology of the scratch was observed by the Scanning Electron Microscope（SEM）.The friction and wear behavior of the DLC thin film under dry sliding against GCr15 steel was evaluated on a ball-on-disc test rig.The results show that the thickness and surface roughness of the prepared DLC thin film by plasma gun are 500 nm and 5～6 nm respectively.The adhesion between the DLC thin film and the substrate is 49 N.The DLC thin film has excellent friction reducing and antiwear behaviors.The friction coefficient of the 20CrNiMo substrate is about 0.65 under dry sliding,while the DLC thin film experienced much abated friction coefficient to 0.148 under the same testing condition.