飞秒激光烧蚀面齿轮材料的流体力学模型和形貌特征研究

Femtosecond Laser Ablation Hydrodynamic Modelling and Morphological Characterisation of Face Gear Materials

在分析研究飞秒激光精微加工面齿轮材料18Cr2Ni4WA机理的基础上,提出一个综合考虑表面张力、Marangoni力、浮力、重力和蒸气反冲压力等多种因素的流体力学模型,描述固液相变和气液相变的过程。通过模型仿真和试验,研究飞秒激光不同脉冲数、能量密度和重复频率对烧蚀凹坑深度和边缘形貌的影响。研究结果表明,随着激光脉冲数和能量密度增加,凹坑深度增大,烧蚀凹坑边缘均有不同程度的凸起;随着激光重复频率增加,烧蚀线凹槽深度增大,当重复频率为300 kHz时,烧蚀形貌较好;当重复频率为500 kHz时,烧蚀线凹槽内有较多熔融堆积物,烧蚀形貌较差。这些研究成果为改善飞秒激光精微加工面齿轮材料表面形貌质量提供了依据。

This study scrutinizes the mechanism of femtosecond laser precision micromachining applied to face gear material 18Cr2Ni4WA.A comprehensive hydrodynamic model is proposed to elucidate the solid-liquid and gas-liquid phase transitions,taking into account factors including surface tension,Marangoni effect,buoyancy,gravity,and vapour recoil pressure.The investigation assesses the effects of varying pulse numbers,energy densities,and repetition frequencies of femtosecond laser on ablation crater depth and border morphology through model simulation and experimental trials.Findings indicate that a rise in laser pulse number and energy density enhances crater depth with divergent degrees of ablation crater edge elevation.An increase in laser repetition frequency escalates ablation line groove depth;optimal ablation morphology is identified at a repetition frequency of 300 kHz,while a poorer form is observed at 500 kHz due to increased melt accumulations within the ablation line groove.These insights offer the groundwork for advancing surface topography quality during femtosecond laser micromachining of face gear materials.