纳秒脉冲激光微焊接316不锈钢

The Micro-welding Research on SUS316 by Nanosecond Pulsed Laser

采用MOPA纳秒脉冲激光器对316不锈钢进行焊接,探索脉宽、频率及焊接速度对焊缝成型的影响,并对纳秒脉冲激光焊接的模式及机理进行了分析。研究表明,采用纳秒脉冲激光在高频下焊接316不锈钢可以得到表面光滑、无气孔缺陷的焊缝,频率是影响焊接的最大因素;当脉宽为30~120 ns时,熔深随频率增加而增大,在中心频率处获得最大值,随后逐渐减小;当脉宽为200~500 ns时,脉宽随频率(>100 kHz)增大而减小;由焊缝截面形貌分析可知,随频率变化存在两种焊接机制,即热导焊和深熔焊;针对不锈钢薄板材料,在长脉宽、高频率下以热导模式进行焊接,可获得良好成形。

The MOPA nanosecond pulse laser was used to weld 316 stainless steel, and the influence of pulse width, frequency and welding speed on weld formation was explored, as well as the mechanism. It was found that a smooth weld seam without porosity defectcould be easily acquired at high laser pulse frequency, which played a key role in welding thin sheets. At the range of 30-120 ns pulse, the weld depth increased with pulse frequency to the maximum at central pulse frequency, and then decreased. While for the longer 200-500 ns pulse, the weld depth decreased as the pulse frequency increasing( >100 kHz). According to the cross-section morphology at the different pulse frequency, there were two different welding regimes: the keyhole(or deep penetration) and conduction regime. It was suitable to welding stainless steel sheets at long pulse and high frequency controlled by conduction mode, resulting in sound weld quality.