Yuan Jiandong, Liang Liang, Jiang Lelun, Liu Xin
Opt Lett. 2018 Apr 1;43(7):1451-1454. doi: 10.1364/OL.43.001451.
The degree of laser pulse overlapping in a laser scanning path has a significant impact on the ablation regime in the laser machining of a micro-texture. In this Letter, a nanosecond pulsed laser is used to prepare the micro-scaled groove on WC-8Co cermet under different scanning speeds. It is observed that as the scanning speed increases, the ablated trace morphology in the first scanning pass transits from a succession of intermittent deep dimples to the consecutive overlapped shallow pits. The test result also indicates that ablated trace morphology with respect to the low scanning speed stems from a plume shielding effect. Moreover, the ablation regime considering the shielding effect in micro-groove formation process is clarified. The critical scanning speed that can circumvent the shielding effect is also summarized with respect to different laser powers.
在微纹理激光加工中，激光扫描路径中的激光脉冲重叠程度对烧蚀状态有显著影响。在本信函中，使用纳秒脉冲激光在不同扫描速度下在WC-8Co硬质合金上制备微尺度凹槽。观察到随着扫描速度增加，首次扫描过程中的烧蚀痕迹形态从一系列间歇性深凹坑转变为连续重叠的浅坑。测试结果还表明，低扫描速度下的烧蚀痕迹形态源于羽流屏蔽效应。此外，阐明了在微槽形成过程中考虑屏蔽效应的烧蚀状态。还总结了针对不同激光功率可规避屏蔽效应的临界扫描速度。
