中文摘要：

为了明确Ti-6A1—4V合金在空间环境下的摩擦磨损失效行为，本文利用中科院兰州化学物理研究所自主研发的空间摩擦学试验系统对Ti-6A1—4V在三种模拟空间环境（高真空、原子氧和紫外辐照）下的摩擦磨损性能进行了系统的研究。采用SEM和EDS对磨损后Ti-6A1—4V和对偶GCrl5钢球的形貌和元素面分布进行了分析，揭示了Ti-6A1—4V在模拟空间环境下摩擦磨损失效机理。用XPS分析Ti-6A1—4V在原子氧辐照后表面元素价态的变化。结果表明：Ti-6A1—4V在大气条件下的摩擦磨损机理为磨粒磨损和粘着磨损；在高真空、原子氧和紫外辐照模拟空间环境下的磨损机理为较严重的粘着磨损、磨粒磨损和塑性变形；相比于大气条件下，Ti-6A1—4V在高真空、原子氧和紫外辐照条件下的粘着磨损加剧，摩擦因数增加；Ti-6A1—4V在原子氧辐照后表面发生了氧化。

英文摘要：

The tribological property and mechanism of Ti-6A1-4V alloy space harsh environment were investigated on the space tribological test system which was made by the State Key Laboratory of Solid Lubrication （LSL）. The simulated space environment including ultrahigh vacuum, atomic oxygen atmosphere and ultraviolet irradiation has been built up in the test system. The worn surface morphologies, compositions of both Ti-6A1-4V and its counterpart GCrl5 steel balls were characterized with scan electron microscopy （SEM） and energy dispersive spectroscopy （EDS）. The surface composition of titanium after atomic oxygen irradiation was analyzed by X-ray photonelectron spectroscopy （XPS）. It has been found that Ti-6A1-4V sliding against GCr15 steel balls under ordinary atmospheric environment is dominated by abrasive and adhesive wear; while server adhesive wear, abrasive wear and plastic deformation under the ultrahigh vacuum, atomic oxygen and ultraviolet irradiation environments; Ti- 6A1-4V was oxidized after atomic oxygen irradiation.