目的 探究在不同黏度合成酯润滑油的作用下，CrN/TiN多层薄膜的摩擦学性能及协同润滑机制。方法 选用聚α烯烃(PAO)与三羟甲基丙烷辛癸酸酯(TME)复配，得到不同黏度梯度的合成油。利用全自动黏度测定仪、倾点测试仪、开口闪点测定器和傅里叶变换红外光谱仪(FTIR)分别对合成油的运动黏度(40、100 ℃)、倾点、闪点和表面官能团进行表征。利用反应磁控溅射技术在316不锈钢和单晶硅片基底表面制备CrN/TiN多层薄膜。采用X射线衍射仪和FIB-TEM表征手段对薄膜的微观结构进行分析，并用纳米压痕仪和划痕仪测试了薄膜的力学性能。利用球–盘式摩擦试验机表征薄膜在干摩擦和油润滑条件下的摩擦学性能，利用XPS对摩擦实验后的磨痕元素价态进行表征。结果 CrN/TiN薄膜具有典型的面心立方结构(FCC)、异质多层结构，且其硬度可达32.2 GPa。在干摩擦条件下，与裸316基体相比，经表面镀制CrN/TiN薄膜后平均摩擦因数由0.95降至0.71，磨损深度由25.0 μm降至16.8 μm。在合成油作用下，316不锈钢-GCr15钢球(钢–钢摩擦副)、CrN/TiN多层薄膜-GCr15钢球(CrN/TiN多层薄膜–钢摩擦副)2种摩擦配副的摩擦因数和磨损率随着合成油黏度的增加均呈现降低趋势，且在同一黏度条件下薄膜试样的磨损率更低。结论 CrN/TiN多层薄膜在PAO与TME复配获得的一系列不同黏度合成油的作用下，随着合成油黏度的增加，薄膜的磨损率和磨损深度逐渐下降，其减摩抗磨性能得到显著提升。通过磨痕表面的XPS分析可知，合成油中极性的酯基吸附在滑动界面，增强了油膜的承载性能，从而减缓了对偶间的摩擦阻力。

Commercially available lubricants mostly use low-polarity polyalphaolefin (PAO) and synthetic esters to enhance the tribological properties of the lubricating oil and the solubility of the additives to comprehensively improve the product performance. In order to simulate the tribological properties of synthetic oil in practical application and the action mechanism of synthetic ester, the nitride composite coating with high hardness, good wear resistance, good oxidation resistance, and anti-adhesion was selected. To explore the tribological properties and synergistic lubrication mechanism of CrN/TiN multilayer films under the action of synthetic oils with different viscosity. Polyalphaolefin was selected and compounded with trimethylolpropane esters (TME) to obtain synthetic oils of different viscosity gradients. The kinematic viscosity (40 ℃ and 100 ℃), pour point, flash point and surface functional groups of the synthetic oils were characterized with a fully automatic viscometer, a pour point tester, an open flash point tester and a Fourier transform infrared spectrometer (FTIR), respectively. The CrN/TiN multilayer films were prepared by the reactive magnetron sputtering technique, and the microstructures of the films were analyzed by means of X-ray diffraction diffractometer and FIB-TEM characterization, and the mechanical properties of the films were tested by nanoindentation. The tribological properties of the films under dry friction and oil lubrication conditions were characterized with a ball-on-disk tribometer. The characterization of element valence by XPS analysis of the wear scar. The synthetic oil obtained by the combination of PAO and TME had high viscosity index, low pour point and high flash point, indicating that it could be applied to a wide temperature range. The CrN/TiN film had a typical face-centered cubic (FCC) structure with a heterogeneous structure and a hardness of 32.2 GPa. The successful preparation of the film was demonstrated by characterizing the microscopic internal structure of the CrN/TiN film. The study of the solid-liquid composite lubrication system found that compared with the steel ball friction pair, the average friction coefficient decreased from 0.95 to 0.71 and the wear depth decreased from 25.0 μm to 16.8 μm after plating the CrN/TiN film on the surface under dry friction conditions. The addition of synthetic oil significantly reduced the friction coefficient of the two friction pairs, and the wear rate decreased gradually with the increase of the viscosity of synthetic oil. Because the ester group in the synthetic oil had strong polarity, it could be better adsorbed on the surface of the friction pair during the friction process to form a dense oil film. In addition, the high viscosity synthetic oil film led to the decrease of friction coefficient, which was consistent with the stribeck curve. For a series of high viscosity index synthetic oils with different viscosity obtained by compounding TME with high-performance PAO base oil, the wear rate and wear depth of CrN/TiN multilayer films decrease with the increase of the synthetic oil viscosity, and the anti-friction and anti-wear properties are significantly improved. XPS analysis of the wear tracks indicate that the adsorption of polar ester groups in the synthetic ester at the sliding interface enhances the load-bearing properties of the oil film and thus slows down the couple friction wear.