不锈钢光纤激光间隙搭接焊信号分析

Monitoring and Detecting of Defects During Fiber Laser Welding

基于自身搭建的光纤激光焊接在线监测系统,实现不锈钢光纤激光焊接过程中搭接间隙的监测。研究发现,当激光搭接焊接过程中出现间隙时,对焊缝的横截面形貌影响较大,但小孔熔深几乎不受影响。但实时监测到的光信号时域幅值及时频域上频率的分布有着明显的变化。利用相关的信号处理方法对信号进行了初步分析,阐述了搭接间隙对光信号的影响规律及机制,同时也为分析搭接过程中等离子体和熔池的动态行为提供了依据。

An online laser-welding monitoring system is performed to monitor the gap of overlap joint in fiber laser welding steel sheet. The results indicated that the gap of overlap joint have a huge impact on welding appearance but nothing to do with welding penetration. Amplitude of optical signal in time domain and frequency distribution in time-frequency domain has a significant change when the defect occurs in the laser welding process. Optical signals are analyzed using signal processing methodologies to reveal intrinsic interaction between optical signals and the gap, it also provide theoretical basis and experimental guidance for analyzing the dynamic behavior of plasma and pool.