W、Mo离子注入对离子镀TiN薄膜表面结构和性能的影响

Effects of W and Mo Ion Implantations on Surface Structures and Properties of Ion-plated Titanium Nitride Coatings

目的进一步改善氮化钛薄膜的摩擦学性能。方法利用金属蒸汽真空弧源(MEVVA)在离子镀TiN薄膜表面进行等剂量W、Mo离子注入。采用扫描俄歇系统、光学三维形貌仪、X射线衍射仪和纳米压痕仪,分别分析了TiN薄膜的离子注入深度、表面形貌及粗糙度、相结构和不同压入深度的薄膜硬度。在球盘滑动摩擦磨损试验机上考察了TiN薄膜的摩擦学性能,并利用扫描电子显微镜和三维形貌仪对其磨损形貌进行分析。结果等剂量离子注入后,TiN表面注入层中W离子的含量明显大于Mo离子,两种离子注入对TiN薄膜的表面形貌和硬度的影响较小。XRD结果表明,W离子和Mo离子注入后均发现了Ti_2N硬质相。两种离子注入均可以不同程度地降低TiN薄膜的摩擦系数和磨损率。结论 W、Mo离子注入均可显著改善TiN薄膜的摩擦学性能,但Mo离子更有利于其摩擦系数的降低,而W离子注入更有利于TiN薄膜磨损率的降低。

The work aims to further improve tribological properties of TiN coatings. W and Mo ion implantations at same doses were performed on ion-plated TiN coatings using metal vapor vacuum arc （MEVVA） source. Ion implantation depth, morphology, surface roughness, phase structure, and nano-hardness at different implantation depth of TiN coatings were ana- lyzed with scanning auger microprobe （SAM）, three-dimensional optical profilometer, X-ray diffractometer （XRD） and nano indentor, respectively. Tribological peroperties of TiN coatings were investigated on a ball-on-disk sliding tribometer. Also,wear appearance was analyzed with scanning electron microscopy （SEM） and three-dimensional optical profilometer. Content of W ions in TiN coatings was obviously higher than that of Mo ions after the same dose implantations. W and Mo ion implanta- tions had less effect on surface morphology and hardness of TiN coatings. The XRD results showed that Ti2N phases appeared on TiN coatings after W and Mo ion implantations. The friction coefficient and wear rate of TiN coatings decreased to different extent after W and Mo ion implantations. Tribological properties of the ion-plated TiN coatings cab be improved by both W and Mo implantations. However, the Mo ion implantation is more conducive to reduction of friction coefficient while the W ion im- plantation is more conducive to redcution of wear rate.