核-壳MoS2@SiO2纳米复合材料的制备及其高温摩擦学性能

Preparation and high temperature tribological properties of core-shell MoS2@SiO2 nanocomposites

  • 摘要: 二硫化钼(MoS2)在高温条件使用易发生氧化导致其摩擦学性能大幅劣化,表现出较高的摩擦系数。为了改善MoS2润滑剂在高温环境下的摩擦学性能,本文通过水热法和改良Stöber法生成核-壳MoS2@SiO2纳米复合材料。通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)及X射线衍射仪(XRD)等对制备的纳米材料的形态、尺寸和组成进行表征。微观结果显示了核-壳结构复合材料的成功制备,平均粒径250 nm。对制备的MoS2@SiO2固体润滑涂层进行高温摩擦实验,并以MoS2涂层作为对比。采用SEM、XRD等对涂层的形貌、结构进行了表征,采用三维轮廓仪对涂层磨损率进行表征。结果表明:MoS2@SiO2涂层在680℃下的摩擦系数为0.2且较平稳,MoS2涂层则迅速失效。MoS2@SiO2涂层耐磨性更好,磨损率比MoS2涂层低25.86%。摩擦实验后MoS2@SiO2涂层磨痕区域仍存在MoS2,有润滑膜覆盖;而MoS2涂层磨痕区的基体完全暴露。由此表明,SiO2外壳的包覆延缓了MoS2在高温下的迅速氧化,且两者协同润滑,延长了涂层的使用寿命。

     

    Abstract: Molybdenum disulfide (MoS2) is easy to be oxidized when used at high temperature, which leads to significant deterioration of its tribological properties, showing a high friction coefficient. In order to improve the tribological properties of MoS2 lubricant under high temperature environment, core-shell MoS2@SiO2 nanocomposites was formed by hydrothermal method and improved Stöber method. The morphology, size and composition of the nano materials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). The micro results show that the core-shell structure composite is successfully prepared, with an average particle size of 250 nm. The high temperature friction test of prepared MoS2@SiO2 solid lubrication coating was carried out, and the MoS2 coating was used as a comparison. The morphology and structure of the coating were characterized by SEM and XRD, and the wear rate of the coating was characterized by a 3D profiler. The results show that the friction coefficient of the MoS2@SiO2 coating at 680℃ is 0.2 and relatively stable, while MoS2 coating rapidly fail. The MoS2@SiO2 coating had better wear resistance, with a wear rate at 25.86%, lower than that of MoS2 coating. After the friction tests, MoS2 still existed in the wear scar area of the MoS2@SiO2 coating, which was covered by the lubricating film. However, the substrate in the wear zone of MoS2 coating was completely exposed. It is thus shown that the encapsulation of the SiO2 shell retards the rapid oxidation of MoS2 at high temperatures and the two synergistically lubricate to prolong the service life of the coating.

     

/

返回文章
返回