Study On Pulsed Laser Ablation Properties Of Gear Material 18Cr2Ni4WA

The precision and surface quality of traditional gear machining in China are not good.Foreign high-precision gear machining machine tools block our country and need to develop new machining methods in order to further improve the surface quality.The beam of the pulsed laser can be focused to a very small range,the processing area is accurate,and the precision can reach the micron or even nanometer level.As laser machining is becoming more and more precise on materials,the use of pulsed lasers to fine-tune gears has become a possible precision manufacturing method.In this paper,based on the discussion of the interaction between pulse laser and metal,the gear material 18Cr2Ni4WA steel is taken as the research object.The damage mechanism and ablation characteristics of the pulse laser ablation gear material are discussed in depth from theory and experiment.The laser fine-finished gear provides a certain reference.For nanosecond pulse ablation of gear materials,a heat transfer model was established based on energy accumulation,and the temperature field was simulated in MATLAB.According to the basic properties of the mating gear material,suitable laser parameters are selected for experiment.The experimental results show that when the single pulse energy is higher in the ablation pit,the outer edge of the pit in the laser ablation area has irregular cracks affecting the roundness and the internal remelt is more,and the surface quality is poor;Under the 10 pulse parameters,the mechanical scratches on the surface of the target material are removed,the roughness value is reduced,and the fine correction processing of the material surface is realized.For the femtosecond laser ablated gear material,after analyzing the heat transfer process of the femtosecond laser,the finite difference method is used to solve the two-temperature equation,and the pulse width,average power to the electroacoustic coupling coefficient,electron and lattice are simulated Significant influence.Based on the classic ablation threshold theory,the experimental platform was built,and the ablation threshold of 18Cr2Ni4WA steel under a single pulse was calculated to be 0.29 J/cm2.The formation process and morphological characteristics of ablated holes under different pulse numbers were analyzed,and ripples of cross structure were found on the inner walls of the holes.By exploring the ablation theory of nanosecond and femtosecond lasers on the gear material,the interaction process of laser and metal was studied.Through the analysis of the ablation characteristics of the material,the ablation morphology and roughness change value under specific laser parameters are given,which provides a certain reference basis for the selection of laser parameters when the pulse laser finely modifies the gear.