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目的 粉末润滑边界层状态预示着润滑条件的优劣.粉末颗粒以其良好的润滑性能和承载能力以及对极端工况的适应性,被广泛应用于诸多领域,因此需对粉末润滑界面的摩擦润滑性能展开深入研究.方法 利用UMT-2多功能摩擦磨损测试仪,结合形状测量激光显微系统对粉末润滑界面边界层的微观形态进行观察和机理分析.重点研究载荷(1、2、4、6 MPa)、速度(2、4、8、16 r/min)、粉末层厚度(1.5、3.5、5.5、7.5μm)以及表面粗糙度(0.389、0.745、1.751、3.112μm)等工况条件对粉末润滑的影响机制.结果较大的接触载荷有利于形成致密的边界层,提高润滑性能.在速度较低时,不利于形成完整、致密的边界层,润滑较差,甚至产生爬行现象,随着速度的增加,润滑效果改善,但过大的速度又会加快粉末耗散.适量的粉末层厚度能够使摩擦界面间形成完整、厚实的边界层,提供良好的润滑能力.粗糙度适当的表面有利于粉末润滑剂存储、边界层的形成以及润滑作用的维持.结论 合理选择接触载荷、速度、粉末层厚度以及试样表面粗糙度有助于提高粉末颗粒的润滑性能.

The boundary layer state of powder lubrication indicates the merits and weakness of the lubrication conditions. Powder particles with better lubrication performance and carrying capacity, as well as the good adaptability to extreme condi-tions, are widely used in many areas. Therefore, the friction and lubrication performance of the powder lubrication interface need studied deeply. With the use of UMT-2 friction and wear tester, the microscopic morphology of boundary layer state of the powder lubrication interface is observed and analyzed combined with shape measurement of laser microscopy. The influence mechanism of load condition (1, 2, 4, 6 MPa), velocity (2, 4, 8, 16 r/min), powder layer thickness (1.5, 3.5, 5.5, 7.5μm) and surface roughness (0.389,0.745, 1.751, 3.112μm) on powder lubrication is studied emphatically. The larger contact load is favorable to form a dense boundary layer, improve the lubrication performance. In the low speed, is not conducive to the forma-tion of a complete dense boundary layer, poor lubrication and even produce crawling phenomenon. With the increase of speed, lubrication effect improved, but too much speed will accelerate the powder dissipation. The appropriate amount of powder layer thickness can form a complete thick boundary layer between the frictional interfaces, providing good lubrication ability. The surface with appropriate roughness is favorable for the powder lubricant storage, the formation of the boundary layer and the maintenance of the lubrication action. Reasonable choice of contact load, speed, powder layer thickness and sample surface roughness helps to improve the lubrication performance.