The Effect of Femtosecond Laser Surface Textured Microdimples Array on Friction Reduction Under Full Oil Lubrication Conditions
P. Zhang, S. Wu, H-J. Wei and L. Chen
In recent years surface texturing and laser surface texturing (LST) have become potential new technologies to reduce friction in the diesel engine. In this paper a strategy of Ti:Sapphire femtosecond laser surface texturing via scanning method was developed to produce microdimple structures on a cast iron sample surface. Gradient scanning velocity method was used to produce two different samples. The mechanism for the effect of surface texturing with microdimples on reducing friction was analysed. The simulation results show that surface texturing has a significant effect on the reducing friction and texturing surface with spherical cap dimple has the highest hydrodynamic pressure. Microdimple on the sample surface was fabricated by LST, which can change the lubrication state of the surface. An experimental study was conducted to analyse the tribological properties of LST with microdimple for use in a cylinder liner. Compared to non-textured surfaces, the laser textured surfaces with dimples shows the significant tribological improvement.
Keywords: Ti:Sapphire femtosecond laser, cast iron, laser surface texturing (LST), friction reduction, microdimple, lubrication, distribution density