采用Nd:YAG激光器对硼磷合金铸铁缸套试样进行激光微孔加工。研究了激光能量密度, 脉冲次数, 重复频率和聚焦条件等参数对微坑几何形貌的作用规律, 采用3D共聚焦显微镜及扫描电镜观察分析了微坑表面形貌和尺度随激光参数的变化。发现随着激光能量密度和脉冲次数的增加, 微坑的直径和深度均逐渐增大, 但增大幅度随能量密度增加而逐渐减小; 微坑直径随激光重复频率的增加而减小, 随着负离焦量的增加而增加; 微坑深度随负离焦量呈先增加后减小的趋势。对激光辐照硼磷合金铸铁的烧蚀阈值进行计算, 在单脉冲辐照条件下硼磷合金铸铁的烧蚀阈值为8.4 J/cm2, 脉冲次数对材料的烧蚀阈值产生累积效应, 烧蚀阈值随脉冲数量增加而减小, 累积系数为0.87。

The surface treatment of the boron-phosphorus alloy cast iron cylinder liner sample was carried out on a Nd: YAG laser. The effects of laser parameters, such as energy density, pulse number, repetition frequency and focusing conditions, on the geometry of the micro-pits were studied through the surface morphology and scale of the micro-pits with 3D confocal microscopy and scanning electron microscopy. The diameter and depth of the micro-pits increase with the increase of laser energy density and the number of pulses, and the increase amplitude decreases with the increase of the energy density; the diameter of the micro-pits decreases with the increase of the laser repetition frequency, while the effect of the amount of negative defocus shows a reverse trend; The depth of the micro-pit increases first and then decreases with the amount of negative defocus. The ablation threshold of laser-irradiated boron-phosphorus alloy cast iron was calculated, the ablation threshold of boron-phosphorus alloy cast iron under single-pulse irradiation was 8.4 J/cm2, and the pulse number has an accumulation effect on ablation threshold, and the cumulative coefficient is 0.87.