20CrNiMo钢表面空心阴极辉光放电制备类金刚石膜

Diamond-like carbon film on 20CrNiMo steel prepared by hollow-cathode glow discharge

在真空炉内以石墨为电极,利用空心阴极辉光放电在20CrNiMo上成功地沉积了类金刚石(Diamond-like carbon,DLC)薄膜,利用激光拉曼(Raman)光谱分析了所制备DLC薄膜的结构;利用原子力显微镜(AFM)分析了DLC薄膜的表面形貌;利用划痕仪测量了DLC薄膜与基体的结合力并用扫描电子显微镜(SEM)观察了划痕形貌;利用球-盘摩擦磨损实验仪对DLC薄膜的耐磨性能进行了研究。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0.6μm,薄膜均匀且致密,表面粗糙度Ra为7～8 nm。类金刚石薄膜与基体结合较紧密,临界载荷达到52 N。DLC薄膜具有优良的减摩性,20CrNiMo表面沉积DLC薄膜后摩擦系数为0.15,较20CrNiMo基体的摩擦系数0.50明显减小,耐磨性能得到提高。

Diamond-like carbon（DLC） thin film was deposited on the surface of 20CrNiMo alloy by hollow cathode glow discharge technique.High purity graphite was selected as the cathode and Ar as working gas.The structure of the DLC thin film was analyzed by laser Raman spectroscopy.Surface morphology of the film was observed by atomic force microscope（AFM）.The adhesion between the DLC thin film and the substrate was investigated with scratch testing.The morphology of the scratch was observed by scanning electron microscopy（SEM）.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 it is feasible to prepare a DLC thin film of 0.6 μm thick by this experimental process.The surface roughness Ra of the film is 7-8 nm.The DLC thin film has a good adhesion with critical load of 52 N by scratch testing.Excellent friction and wear-resistant behavior of the film is observed.Friction coefficient of the 20CrNiMo substrate is about 0.50 under dry sliding against steel,while the DLC thin film exhibited much lower friction coefficient of 0.15 under the same testing condition.