Evaluation of Tribological Performance of High Functional Surface Midified Machine Element under High Temperature in High Vacuum

为了评价高功能改性表面的摩擦学性能，在高温高真空条件下进行了综合试验和分析，研制了多种高性能滑动材料，为了弄清表面改性对滚动接触疲劳强度的影响，对表面改性的轧辊进行了高温高真空试验，用边界元法分析了它们的接触压力和次表面应力。采用双筒摩擦磨损试验机对不同化学镀镍层进行了摩擦磨损试验，并利用有限元分析方法研究了镀层中弥散颗粒对摩擦磨损性能的影响。当分散颗粒的弹性模量小于基体的弹性模量时，分散颗粒周围的最大剪切应力和Mises应力变大，导致磨损增加。指出了最佳磨粒尺寸的确定方法，并利用轮廓仪和激光扫描显微镜对各种磨损表面的分形维数进行了分析，并将其应用于磨损表面的评价。显然，用这两种仪器分析分形维数可以获得更多有益的信息。

In order to evaluate the tribological characteristic and peformance of high functional modified surface, the comprehensive experiment and analysis were performed under high temperature in high vacuum.Kinds of high functional sliding materials were wear-tested under high temperature in high vacuum and the information of their ability were obtained.In order to clarify the influence of surface modification on rolling contact fatigue strength the surface modified rollers were fatigue-tested and their contact pressure and subsurface stresses were analysed with the boundary element method. The reason why the improvement of rolling contact fatigue strength by surface modifications would be due to the reduction of contact pressure and subsurface stresses.Various electroless Ni platings were wear-tested with a two-cylinder test machine and the influence of dispersed particles in the plated layer on friction and wear behaviors was investigated with the finite element method analysis. When the elastic modulus of the dispersed particles is smaller than that of the matrix, the maximum shear stress and Mises stress around the dispersed particles become large, resulting in wear increasing. It was indicated how to decide the optimum particle size.Fractal dimensions of various worn surfaces were analysed with data measured with a profile meter and a laser-scanning microscope, and applied to the evaluation of worn surface. It was obvious that the more beneficial information could be obtained using fractal dimensions analysed with both instruments.