紫外纳秒激光加工316L不锈钢微槽尺寸和形貌控制研究

Study on Size and Morphology Control of 316L Stainless Steel Microgrooves Processed by Ultraviolet Nanosecond Laser

采用波长355 nm的纳秒激光对316L不锈钢进行表面微纳加工,研究了微米级沟槽的尺寸控制、紫外激光加工热影响及改善加工质量的方法。结果表明,选择合理的搭接间距、通过控制搭接个数和扫描次数可以实现微槽尺寸的精确控制。紫外激光加工金属的热影响很小,不存在明显热扩散,近加工区组织稳定。大气中紫外激光加工存在氧化,氧化程度随着扫描次数的增大非线性提高,且激光光束扫描边缘区域氧化程度高于中心区域。加工表面呈典型的液化喷溅形貌,未加工表面容易附着熔化飞溅残渣。涂料、吹氮和酸洗可以去除附着在未加工区域的氧化飞溅物,吹氮和酸洗还能去除加工区的溅落物,并且降低表面氧化。

Surface texturing of 316 L stainless steel was carried out by nanosecond laser with 355 nm wavelength. Size control of micron groove, thermal effect of ultraviolet processing and methods of improving texturing quality were studied. The results show that the precise control of micron groove size was achieved by choosing reasonable scanning spacing, number and repetition number.The thermal effect of ultraviolet laser processing metal was very small, there is no obvious thermal diffusion, and the micro-structure near the processing zone was stable. There was oxidation in ultraviolet laser processing in the atmosphere. The oxidation degree increased nonlinearly with the increase of repetition numbers, and the oxidation degree in the edge region of laser beam scanning was higher than that in the center region. Processed surface showed typical liquefaction splash morphology, and the melting splash residue adhered to unprocessed surface easily. Coating, nitrogen blowing and pickling could remove oxidized spatters adhering to the unprocessed area. Nitrogen blowing and pickling could also remove the spatters in the processed area and reduce surface oxidation.