目的 研究大气等离子喷涂Al2O3涂层在高硬配副下的摩擦磨损行为。方法 通过大气等离子喷涂(APS)制备了厚度约为380 μm的Al2O3涂层，利用纳米压痕仪测量了Al2O3涂层和两种摩擦副的硬度和弹性模量。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)对喷涂粉末、涂层以及磨痕的相结构和形貌进行了表征分析，通过X射线能量色散谱仪(EDS)分析了涂层磨痕中对偶元素的转移。另外，还通过CSM摩擦机系统地研究了该涂层的摩擦磨损行为。借助X射线光电子能谱仪(XPS)分析了磨痕中的化学组成。结果 制备的Al2O3涂层主要以γ-Al2O3相为主，且存在一定孔隙，并出现层状结构。在摩擦实验中发现，在同一摩擦副下，Al2O3涂层的摩擦系数随着载荷的增加而逐渐降低，磨损率随之增大。由于摩擦配副力学性能的差异，使Al2O3涂层表现出不同的摩擦磨损行为。以Si3N4为摩擦副时，Al2O3涂层的摩擦系数较小，但磨损率大，磨损机制主要是磨粒磨损和粘着磨损。在摩擦过程中，Si3N4对偶副会与空气中的水反应，生成少量具有润滑效果的Si(OH)4胶体。以WC为摩擦副时，Al2O3涂层的摩擦系数大，但磨损率低，磨损机制主要是粘着磨损和磨粒磨损，并伴有疲劳磨损。在摩擦过程中，由于产生了摩擦热，Al2O3涂层磨痕表面的γ-Al2O3相转变为α-Al2O3相，摩擦配副的硬度和弹性模量越大，摩擦系数越高，γ-Al2O3相的转变也越多。结论 因高硬度的Si3N4和WC对偶球拥有不同的力学性能，对大气等离子喷涂制备的Al2O3涂层的摩擦磨损机理有显著的影响，并且在摩擦过程中，涂层磨痕内的γ-Al2O3相会向α-Al2O3相转变。

This paper aims to study the friction and wear behavior of Al2O3 coating with atmospheric plasma spraying under high hardness. The Al2O3 coating was prepared by atmospheric plasma spraying (APS) with a thickness of 380 μm. Besides, the phase structure and morphology of the powder and as-sprayed coating were characterized by X-ray diffractometer (XRD) and scanning electron microscope (SEM). The X-ray energy dispersive spectrometer (EDS) was employed to analyze the transfer of grinding crack elements, while Al2O3 coating and two kinds of hardness and elastic modulus of friction pair were measured with the help of the nano indentation apparatus. In addition, the friction and wear behavior of the coating was systematically studied by the CSM friction machine. The chemical composition of the wear marks was analyzed by X-ray photoelectron spectroscopy (XPS). The Al2O3 coating was mainly composed of γ-Al2O3 phase, with a large number of pores and layered structure. In the friction experiment, it is found that under the same friction pair, the friction coefficient of Al2O3 coating decreased gradually with the increase of load, and the wear rate increased. Due to the differences in mechanical properties of friction pairs, Al2O3 coatings exhibited different frictional wear behaviors. When the friction pair was Si3N4, the friction coefficient of Al2O3 coating was small, but the wear rate was large. The friction mechanism was mainly abrasive wear and adhesive wear. At the same time, Si3N4 reacted with water in the air to form Si(OH)4 colloid with lubricating effect during the friction process. When the friction pair was WC, the friction coefficient was large, but the wear rate was low. The friction mechanism was mainly adhesive wear and abrasive wear, accompanied by fatigue wear. The γ-Al2O3 phase inversion occurred in Al2O3 coating on the surface of wear trace due to friction heat. The higher the friction coefficient was, the greater the hardness and elastic modulus of the friction pair was, and the more serious the γ-Al2O3 phase inversion was. The high hardness of Si3N4 and WC dual spheres has a significant effect on the friction and wear mechanism of Al2O3 coating prepared by atmospheric plasma spraying, and the γ-Al2O3 in the wear marks will change to α-Al2O3 during the friction process.