65Mn钢基体CrTiAlN微纳米复合膜的制备与抗高温磨损性能研究

Investigation of Preparation Technologies and Tribological Properties at High- Temperature of CrTiAlN Composite Films on 65Mn Steel Substrates

采用多弧离子镀在活塞环65Mn钢基体表面制备CrTiAlN微纳米复合膜,研究了CrNx过渡缓冲层与工作负偏压对CrTiAlN微纳米复合膜性能的影响规律,采用X射线衍射(XRD)、扫描电子显微镜(SEM)、划痕仪、纳米硬度仪和发动机台架试验装置,系统分析了薄膜相结构、表面形貌、纳米硬度和抗高温摩擦磨损性能。结果表明:当N2含量为45%时,CrNx薄膜中主要以CrN(220)相为主,此时复合膜结合强度相对较高;复合膜厚度随负偏压增大而减小,纳米硬度随负偏压增大而增大,当偏压为–200V时,CrTiAlN微纳米复合膜的晶粒较为细小。采用优化工艺沉积的CrTiAlN复合膜具有优异的抗高温粘着磨损性能,优于CrN膜和电镀Cr,最后对3种活塞环涂层的抗高温磨损机理进行了分析讨论。

CrAITiN composite coatings were deposited on the surface of 65Mn steel substrates for piston rings by multi-ion plating technology at various buffer interlayer and negative bias voltage to decrease the wear of both ring and cylinder and increase the service life for piston rings. The structure, surface morphology, nano hardness and tribological properties at high temperature of the CrAITiN composite coatings were tested by XRD, SEM, nano hardness tester and engine test equipment, respectively. The results show that when the nitrogen content is 45%, the main phase in the CrNx buffer interlayer is CrN （220） and the adhesion strength of CrAlTiN coatings is relatively higher. With the increasing of negative bias voltage, the thickness of CrAITiN coatings is decreased and the hardness is increased. When the bias voltage is -200 V, the crystal size of CrAITiN coatings is fine. And the CrAlTiN composite coatings show very good oxidation resistance and high temperature wear resistance, better than the CrN films and plating chromium. Then the wear resistance mechanism at high temperature for the above three kinds of piston coatings was analyzed.