辉光放电辅助脉冲激光沉积CN_x涂层工艺

Glow discharge-assisted pulsed laser deposition of CN_x coatings

采用直流辉光放电辅助PLD(脉冲激光沉积)法制备了CNx涂层,通过正交试验研究了气压、激光通量、放电功率密度和靶基距等工艺参数对CNx涂层的氮含量、摩擦因数和磨损率的影响,利用扫描电镜(SEM)、X射线光电子能谱仪(XPS)和球-盘式微型摩擦仪对涂层的表面形貌、化学成分以及摩擦学特性进行了表征。结果表明,辉光放电辅助PLD制备的CNx涂层比传统PLD涂层光滑,且工艺参数对涂层表面形貌的影响较小。激光通量对涂层的氮含量、摩擦因数和磨损率的影响较为显著,放电功率密度的影响最小。涂层的耐磨性随涂层氮含量的升高而降低。当气压为12 Pa、激光通量为6.7 J/cm2、放电功率密度为30 m W/cm2和靶基距为37 mm时,涂层中氮原子分数为32.2%,沉积速率为0.83μm/h,摩擦因数为0.122,磨损率为1.13×10-13 m3/(N·m)。

A CNx coating was prepared by direct-current glow discharge-assisted pulsed laser deposition （PLD） technique, and the effects of the process parameters including gas pressure, laser flux, discharge power density, and distance between target and substrate on the content of nitrogen, friction coefficient, and wear rate of the CNx coating were studied by orthogonal test. The surface morphology, chemical composition, and tribological behavior of the coating were characterized by scanning electron microscope （SEM）, X-ray photoelectron spectroscope （XPS）, and ball-on-disk micro-tribometer, respectively. The results indicated that the CNx coating prepared by glow discharge-assisted PLD is smoother than the coating prepared by traditional PLD method, and the process parameters have a slight effect on its surface morphology. Laser flux has a remarkable influence on the content of nitrogen, friction coefficient, and wear rate of the CN, coating, while the discharge power density has the minimal effect. The wear resistance of the coating is decreased with the increasing of nitrogen content of the coating. The CN, coating obtained at gas pressure 12 Pa, laser flux 6.7 J/cm2, discharge power density 30 mW/cm2, and distance of target to substrate 37 mm has the following properties： nitrogen content 32.2at.%, deposition rate 0.83 p.m/h, friction coefficient 0.122, and wear rate 1.13 × 10-13 ma/（N.m）.