Dry lubrication and transfer lubrication of rolling contacts by self-regenerating molybdenum oxide coating systems

计划项目中的研究工作开辟了通过钼基涂层对受滚动载荷影响的摩擦接触进行可靠固体润滑的可能性。开发了一种稳定的涂层工艺，可应用于不同的体系。纳米磨损试验用于表征和模拟单个涂层组分的磨损行为。在FE8试验台上进行了轴向圆柱滚子轴承的滚动轴承试验，赫兹压力高达1 GPa，与未润滑的标准轴承相比，干润滑轴承的使用寿命显著增加；结果优于WC/C涂层轴承。结果表明，Mo和MoO3的组合是一种新型的干润滑剂。在滚动接触中，MoO3作为润滑剂被分散，并通过摩擦氧化从Mo储层中连续形成。此外，在混合动力轴承中演示了传递润滑。在这种情况下，在转移阶段发生了磨合过程，随后导致了稳定的运行条件。现在，所需资金的重点将是将结果扩展到更复杂的轴承几何形状和更大的轴承，更深入地了解润滑机制并更好地控制它们，从而使组件的操作行为可预测。IMKT在摩擦学层分析方面的丰富经验将用于进一步研究MoO3传递润滑。研究的中心目标是更详细地阐明MoO3传递润滑的作用机理，并更深入地研究MoO3对微观结构边缘区域的影响。传递膜形成的描述是通过扩展磨损模型来实现的，该模型描述了由“负”磨损形成的层，随后是稳态阶段，直到层退化。

The research work in the planned project opens up the possibilities of operationally reliable solid lubrication of tribological contacts subjected to rolling loads via Mo-based coatings. A stable coating process was developed which can be transferred to different systems. Nanowear tests were used to characterize and model the wear behavior of the individual coating components. In the rolling bearing tests with axial cylindrical roller bearings on the FE8 test rig with Hertzian pressures of up to 1 GPa, a significant increase in operating life was demonstrated for the dry-lubricated bearings compared to unlubricated standard bearings; the results were even better than those obtained for bearings coated by means of WC/C. It was shown that the combination of Mo and MoO3 represents a new type of dry lubricant. In rolling contact, the MoO3 is finely dispersed as a lubricant and is continuously formed from the Mo reservoir by tribo-oxidation. In addition, transfer lubrication was demonstrated in a hybrid bearing. In this case, a running-in process took place in the transfer phase, which subsequently led to a stable operating condition. The focus in the requested funding will now be to scale the results to more complex bearing geometries and larger bearings, to understand the lubrication mechanisms more deeply and to control them better, and thus to make the operating behavior of the components predictable. The IMKT's extensive experience in the analysis of tribological layers will be used for further research into MoO3 transfer lubrication. The central research objective is to clarify the mechanism of action of transfer lubrication by MoO3 in more detail and to investigate the influence on the edge zones of the microstructure in greater depth. The description of the transfer film formation is realized by an extended wear model, which describes the layer build-up by a "negative" wear and subsequently the steady state phase until the layer degradation.