Effect of Textured Surface on the Frictional Property of 40Cr Steel under High Load and Line Contact

The same depth and area density of micro-texture with diameter varying from 20μm to 80μm were designed and manufactured by laser surface texturing on the surface of 40Cr steel. All the surfaces were measured by using non-contact 3D optical profiler Talysurf CCI Lite and characterized by ISO 25178. This study conducted a series of frictional experiments on a JPM-1 two-disc tribo-tester under heavy load(hertzian contact pressure greater than 1 GPa). The frictional property of these specimens and the influence of 3D characterization parameters of the surface morphology to tribological performance was studied in different operating conditions. It is found that the micro-texture surfaces with diameters of 20μm and 80μm had advantage over smooth surface in friction reduction under lubrication. The influences of load, rotational speed, sliding-rolling to friction coefficient were different. The effect of micro-texture was the most pronounced under low load, high rotating speed and slip ratio. In addition, the relationship between frictional property of 40Cr and 3D characterization parameters(e.g S_a、V_v、S_pc、V_mp、S_xp) were investigated under heavy load.