Investigation Of Lubrication Theory And Tribological Characteristics Experiment On Crosshatched Grooves Surface With Laser Micro-texture

The microscopic geometry of the friction pair surface has an important influence on its tribological properties and it is an important indicator for measuring the performance of mechanical parts.Theoretical research and engineering practice have shown that proper surface texture treatment on the friction pair surface can effectively improve its tribological properties.As a kind of texture of surface texture,the crosshatched grooves can not only play the role of lubrication and friction reduction,but also can store and transport lubricating oil.It has become one of the hotspots in the field of surface texture tribology research.At present,the research on the tribological properties of crosshatched grooves is mainly researched by experiment,lack of systematic and deepgoing theoretical research.In this paper,the theoretical model of crosshatched grooves texture lubrication is established.The numerical analysis method is used to systematically study the geometric parameters of the crosshatched grooves and the influence of roughness on the lubrication performance,and compare it with the experimental research.Firstly,based on the mass conservation cavitation boundary condition and Reynolds equation,the theoretical model of hydrodynamic pressure lubrication on the crosshatched grooves texture surface is established.The multi-grid method is used to numerically solve the pressure distribution of the lubricating oil film on the crosshatched grooves texture surface,and the influence of the geometric parameters of the crosshatched grooves on the hydrodynamic lubrication performance of the fluid.The results show that different geometric parameters have different effects on the thickness of the lubricating oil film and the average oil film pressure.Compared with the groove spacing and overlap coefficient,the groove width,depth and cross angle have significant effects on the hydrodynamic lubrication performance of the textured surface.The average oil film pressure increases with the increase of the groove width and the cross angle.There is an optimum groove depth and spacing,which makes the hydrodynamic pressure lubrication the best,but the optimal groove spacing is relatively weak;the overlap coefficient of the grooves has little effect on the hydrodynamic effect and can be ignored.Then,the theoretical model of hydrodynamic lubrication about the crosshatched grooves textured surface with surface roughness is established,and the influence of surface roughness on hydrodynamic lubrication performance about the crosshatched grooves textured surface is explored.It is found that the influence of surface roughness on the average pressure of the lubricating film increases with the groove width.The optimal groove depth and spacing make the hydrodynamic lubrication performance about the crosshatched grooves textured surface optimal.The effect on the average pressure of the lubricating film increases as the groove spacing increases.The the average pressure of the lubricating film increases first and then decreases with the increase of the cross angle.The influence of surface roughness on the average pressure of the lubricating film increases with the cross angle.The overlap coefficient has almost no effect on the average film pressure,and the effect of roughness on t the average pressure of the lubricating film is hardly affected by the overlap coefficient.Finally,using the MLPS-50 PS multi-functional picosecond machine to process different geometrical parameters crosshatched grooves on the 45# steel sample surface,through the experiment on the Rtec MFT-5000 reciprocating friction and wear equipment,it is found that the operating condition has great influence on the tribological performence of the crosshatched grooves surface texture.The lubrication and anti-friction effect is better under high speed and light load.It is also found by comparison that there is the best groove depth and groove spacing to minimize the average friction coefficient,which is consistent with the results of theoretical study.But at the same time,it is found that the results of the cross angle have certain errors with the theoretical study,which may be due to the fact that the experimental conditions have not reached the fluid lubrication state and the film rupture due to the contact boundary problems.