飞秒激光切割金属的表面粗糙度

Surface roughness of cutting metal by femtosecond laser

为提高激光切割金属的表面质量,用不同工艺参数的飞秒激光单次切割厚度为100μm的铜箔,并采用弱激光表面修复加工方法,取单次切割后最低粗糙度约为694 nm的表面进行弱激光再扫描修复。研究结果表明：高能量飞秒激光切割金属存在热效应,扫描电镜显示表面有颗粒氧化物,实验得到再扫描修复加工的优化工艺参数为：再扫描进给深度为10μm,速度为100μm/s,单脉冲能量为50~100μJ。在最优条件下,再扫描1次的表面粗糙度达220~250 nm,再扫描3次的表面粗糙度小于130 nm。该方法能有效提高飞秒激光切割金属的表面质量。

In order to improve the quality of metal surface cut by laser, 100 μm thick copper foils were cut by femtosecond laser with different parameters. Processing method of weak femtosecond laser rescanning was used to repair the copper surface whose minimum roughness was about 694 nm after the first cut. The results show that there is thermal effect when the copper foils are cut by high intensity femtosecond laser. Granular oxide can be found on the surface by scanning electron microscope. The optimum rescanning parameters of the surface repairing method are as follows： the feed depth is 10 μm, the speed is 100 μm/s and the single pulse energy is 50-100 μJ. Under the optimum condition, the surface roughness can be improved 220-250 nm after single-pass of rescanning. And surface roughness is lower than 130 nm after three times of rescanning process. Thus it can be concluded that the rescanning processing method can improve the surface quality of metal cutting by femtosecond laser effectively.