Low Friction Mechanism Survey of Tungsten Disulfde by Using XRD, XPS, and XAFS
Low Friction Mechanism Survey of Tungsten Disulfde by Using XRD, XPS, and XAFS
复制标题
使用 XRD、XPS 和 XAFS 研究二硫化钨的低摩擦机理
DOI：
10.1007/s11249-021-01428-8
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发表时间：
2021
影响因子：
3.2
通讯作者：
Keizo Hashimoto
中科院分区：
文献类型：
--
作者：
Ayaka Takahashi; Yasuo Takeichi; Masao Kimura; Keizo Hashimoto
固体润滑剂用于润滑各种航天器和运载火箭的机械设备。二硫化钨 (WS2) 是一种固体润滑剂，可在外太空高温下用于多种应用。在本研究中，使用 WS2 粉末（直径 2.0 μm）通过喷丸方法在金属盘上涂覆 WS2 涂层。采用销盘式旋转摩擦试验机在真空高温条件下进行摩擦实验，研究WS2的摩擦特性。 WS2喷丸涂层的摩擦系数在室温下极低，并且随着测试温度的升高而增加。尽管如此，WS2 涂层在高温下表现出优异的摩擦性能，因此它们适用于 400°C 的真空环境。所有 WS2 样本均显示 (0002) 基面平行于椎间盘表面的首选方向。在磨损过程中，第二近邻原子的原子排列从原始位置发生扭曲。经 400°C 退火的喷丸 WS2 试样的室温摩擦测试表明，在 (0002) 平面上具有较高平面对准度的试样的摩擦系数大于具有平面缺陷的试样的摩擦系数。堆垛层错和位错等晶格缺陷通过极低的剪切应力辅助相邻硫原子在（0002）面上的滑动。图形摘要
Solid lubricants are used to lubricate the mechanical equipment of various spacecraft and launch vehicles. Tungsten disulfide (WS2) is one of the solid lubricants that can be used in a variety of applications at elevated temperatures in outer space. In this study, WS2coatings on a metal disc were applied via the shot peening method using WS2powder (diameter of 2.0 μm). Friction experiments were carried out to investigate the friction characteristics of WS2using a pin-on-disc-type rotary tribometer at high temperature in a vacuum. The friction coefficients of the WS2shot peening coating were extremely low at room temperature and increased with the test temperature. Nevertheless, WS2coatings demonstrated superior frictional properties at elevated temperatures and thus they are applicable at 400 °C in vacuum. All WS2specimens showed a preferred orientation of the (0002) basal plane parallel to the disc surface. Atomic arrangements of the second nearest neighbor atoms were distorted from the original sites during the wear process. The room temperature friction tests of the shot peened WS2specimen, annealed at 400 °C, demonstrated that the friction coefficients of the specimen with a higher degree of planar alignment on the (0002) plane were larger than those of the specimens with planner imperfections. Lattice defects such as stacking faults and dislocations assisted in the sliding motions of the adjacent sulfur atoms on the (0002) plane by extremely low shear stress.Graphic Abstract