为降低活塞环与缸套摩擦副的磨损及延长活塞环的使用寿命,本文采用多弧离子镀在活塞环表面制备了CrN及CrTiAlN复合膜,比较研究了Cr电镀层与CrN,CrTrAlN复合膜的纳米硬度及高温摩擦磨损性能,采用X射线衍射、扫描电子显微镜、能谱仪、纳米硬度仪和发动机台架试验装置,系统分析了CrTiAlN复合膜的成分、相结构、表面形貌、纳米硬度和抗高温摩擦磨损性能,研究结果表明:CrTiAlN复合膜的主要组成成分为Cr,Ti,Al,N,复合膜中含有CrN,CrEN,TiN和非晶的AlN相。CrTiAlN复合膜表面组织致密,均匀分布着许多颗粒,最大的达400nm以上,而最小的仅几十纳米。断面结构为纤维状的柱状晶组织。CrN,CrTiAlN复合膜比电镀Q具有较优的力学性能和高温摩擦磨损性能,与缸套匹配性能良好,最后对三种活塞环涂层的摩擦副匹配机理进行了分析讨论。
The CrN and CrAlTiN composite films were deposited by multi-are ion plating on the surfaces of piston ring to improve its mechanical properties. The microstructures and mechanical properties of the films were characterized with X-ray diffraction, energy dispersive spectroscopy, scanning electron microscopy and conventional mechanical probes. The impacts of the coating conditions on its textures were also studied. The results show that the chemical contents of the CrAlTiN composite coatings are mainly Cr, Al, Ti and N, and that the crystalline phases of Cr, CrN, Cr2N, TiN and amorphous AlN were observed. The fairly dense and compact CrAlTiN films have uniformly distributed nano-grains with size ranging from tens nm to 400 nm. When it comes to the mechanical properties, including wear resistance, surface hardness, and tribological matching with the cylinders at high temperatures, the CrN and CrAlTiN coating outperforms the electroplated Cr coating. Possible mechanisms were also tentatively discussed.