Simulation Study And Experiment Of Femtosecond Laser Ultrafine Polishing Of 304 Stainless Steel

Femtosecond lasers are different from conventional continuous lasers in that they have extremely narrow pulse widths and high peak powers,enabling heatless processing of materials.It is also often used for ultra-fine processing because of its high etching accuracy and small and controllable processing area.At present,in the flexible screen substrate material,304 stainless steel to superior performance to win,but its surface quality requirements will be relatively high.In this paper,we try to use the double temperature equation model,calculate the change of electron and lattice temperature,explore the removal mechanism of the femtosecond laser on the metal material,analyze the polishing process,and use the femtosecond laser to achieve ultrafine polishing of 304 stainless steel for industrial production,and the research content of this paper is as follows.In this paper,we use finite element simulation software to establish a two-dimensional model with the size of 20?m× 10?m,disregard the chemical changes in the polishing process and the influence of the initial roughness on the polishing results,reasonably carry out the mesh division,and use the PDE module to solve the dual-temperature equation.The metal material used in the simulation is 304 stainless steel,set different power of the single pulse laser ablation of the target,solved to obtain the electron and lattice temperature with the laser power and laser pulse width,while using the phase indicator to obtain the ablation radius and ablation depth,and analyze the ablation depth and ablation radius with the variation of femtosecond laser power,the study concluded that the ablation range in the polishing process is greater than the laser spot diameter The study concluded that the ablation range in the polishing process is larger than the laser spot diameter,and the electron-lattice coupling time is less than 20 ps,so it is known that the femtosecond laser polishing 304 stainless steel without thermal effects.The laser used in the experiment is a femtosecond laser,firstly,the target is scratched by nano-scratcher to get the initial surface,and the polishing experiment is carried out on 304 stainless steel target under different laser processing parameters.Firstly,different power of femtosecond laser was used to scan the 304 stainless steel target to get the law of the power of the femtosecond laser on the polishing results,and the best surface quality was obtained at the power of 0.75W;secondly,the effect of different scanning times on the polishing results when the power was 0.75 W was used.The experimental results show that:with the increase of power,the surface quality first becomes better and then worse,the reason is that the depth of ablation will be different with different power;with the increase of scanning times the surface quality first becomes better,and then the change is not large,the reason is that the same power and scanning speed,the depth of laser removal of material remains the same.Through the simulation to verify the dual-temperature equation,the ablation depth and ablation radius variation law,through the experiments to verify the correctness of the simulation model,but also from the femtosecond laser polishing 304 stainless steel for "cold polishing".