飞秒激光烧蚀齿曲面的复耦合模型及形貌影响  

Complex Coupling Model and Morphology Effect of Femtosecond Laser Ablation of Tooth Surface

作　　者：明兴祖 李学坤[2] 米承继 何国旗[2] 周贤[1] 黎超 明瑞 MING Xingzu;LI Xuekun;MI Chengji;HE Guoqi;ZHOU Xian;LI Chao;MING Rui(School of Mechanical Engineering,Hubei University of Arts and Science,Xianyang 441053,China;School of Mechanical Engineering,Hunan University of Technology,Zhuzhou 412007,China;Technology Center of Zhuzhou Gear Co.,LTD.,Zhuzhou 412000,China)

机构地区：[1]湖北文理学院机械工程学院,襄阳441053 [2]湖南工业大学机械工程学院,株洲412007 [3]株洲齿轮有限责任公司技术中心,株洲412000

出　　处：《光子学报》2023年第4期10-21,共12页Acta Photonica Sinica

基　　金：国家自然科学基金(No.51975192);湖南省自然科学基金(Nos.2021JJ30214,2021JJ50042,2021JJ50033);湖北省高等学校优秀中青年科技创新团队(No.T201919)。

摘　　要：针对飞秒激光烧蚀齿曲面过程中能量累积效应与变离焦效应对齿面形貌与烧蚀尺寸的影响问题,建立飞秒激光烧蚀复耦合模型,通过有限差分法求解得到激光烧蚀面齿轮材料18Cr2Ni4WA的电子与晶格在不同的脉宽与能量密度下的温度变化分布,对烧蚀凹坑的深度及半径进行仿真。考虑激光束在加工齿面时,与被加工齿面之间存在倾斜角,根据光斑能量分布方式得到齿面底角与激光能量的定量关系,结合焦半径与折射率的变化,对飞秒激光烧蚀齿面深度、半径与形貌进行研究。通过实验得到当激光能量密度为1.783 J/cm^(2)且被加工齿面底角过大时,激光能量降低烧蚀过程只发生在材料表面;当能量密度为2.376 J/cm^(2)、激光脉冲数为3000时,烧蚀凹坑的微结构细密良好。研究结果表明飞秒激光烧蚀曲面时,激光有效能量随着倾斜角的变化降低,同时激光光斑的能量分布影响了烧蚀凹坑深度的变化,可为提高飞秒激光加工齿曲面质量提供参考。The two-temperature model is commonly used to analyze the femtosecond laser ablation process,simulating laser ablation by analysing the coupling of electrons to the lattice and the temperature change.Due to the extremely short pulse width of the femtosecond laser,a variety of dynamic effects are generated during the ablation process,such as energy accumulation effects,defocusing effects and dynamic material absorption rate effects.Therefore,when studying the femtosecond laser ablation process,it is necessary to consider the effect of dynamic effects on the size of the ablation.The existing ablation models need to be improved to improve the efficiency of femtosecond laser processing and the accuracy of ablation models.In this paper,a quantitative relationship between the variation in the number of pulses and the total laser energy absorbed by the material is established for the energy accumulation effect;the laser energy at different ablation depths is also obtained based on the effect of the variation in ablation depth on the laser focus radius.By coupling the energy accumulation effect and the defocusing effect into the dual-temperature model,the temperature distribution of the electrons and lattice of the laser-ablated surface gear material 18Cr2Ni4WA is obtained by the finite difference method at different pulse widths and energy densities.The temperature at equilibrium is around 3000 K,which reaches the cavitation temperature of the face gear material 18Cr2Ni4WA,and the material can be ablated,and the depth and radius of the ablation crater are 4.07μm and 24.23μm,respectively.Considering that the surface of the material processed by the femtosecond laser is mostly a complex curved surface,the angle between the laser beam and the surface to be processed during the processing of the curved material will change due to the vertical writing of the laser beam.The laser beam is tilted to ablate the surface of the material and only the laser component perpendicular to the material surface acts on the microstructure

关 键 词：飞秒激光 能量累积 变离焦量 复耦合模型 曲面加工 18CR2NI4WA 激光烧蚀 齿面形貌 

分 类 号：TN24[电子电信—物理电子学]