Laser micro-grooving has excellent potential to improve the surface properties of metals. In this study, high-speed micro-grooving of the surfaces of mild steel SS400 and aluminum alloy A1050 was investigated using a single-mode continuous-wave fiber laser with an average power of 200 W. Experiments were conducted at laser beam scanning speeds of 1 to 6 m/s. The incident angle of the laser beam in the plane perpendicular to the scanning axis was varied from 0 to 60°. A relatively deep groove (approximately 30 µm in depth) and a high upheaval (10 µm in height) were formed along the scanning line at an incident angle of 45° on the SS400, whereas only shallow grooves were formed on A1050. The micro-groove formation mechanism was discussed on the basis of high-speed camera observation, groove shapes, and the thermophysical properties of the metal. Asymmetric molten metal flow and solidification around the keyhole are thought to play important roles in micro-groove formation. Although the laser irradiation conditions must be optimized according to the thermophysical properties of the material, angled laser irradiation has the potential to effectively form micro-grooves.

中文翻译：

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单模连续波光纤激光器的角度辐照对金属进行高速微刻槽

激光微刻槽具有改善金属表面性能的出色潜力。在这项研究中，使用平均功率为200 W的单模连续波光纤激光器研究了SS400和铝合金A1050的低碳钢表面的高速微刻槽。 1至6 m / s。激光束在垂直于扫描轴的平面上的入射角在0到60°之间变化。在SS400上，沿扫描线以45°的入射角形成了一个相对较深的凹槽（深度约30 µm）和一个高起伏（高度10 µm），而在A1050上仅形成了浅凹槽。在高速相机观察，沟槽形状和金属的热物理性质的基础上，讨论了微沟槽的形成机理。人们认为，锁孔周围的不对称熔融金属流动和凝固在微沟槽形成中起着重要作用。尽管必须根据材料的热物理性质优化激光辐照条件，但成角度的激光辐照有可能有效形成微沟槽。