搭建了一个有辅助光源的光纤激光焊接质量同轴监测系统, 着重研究了激光对接焊镀锌钢时的质量监测。首先利用光谱仪采集了光纤激光焊接镀锌钢的等离子体光谱分布, 实验结果表明波长在430～480 nm、620～650 nm之间等离子体辐射强度较大, 所以采取在滤光系统中使用绿色波段滤波片(其中心波长为532 nm)降低焊接过程中产生的等离子体对焊接质量监测的干扰; 其次为了更好的采集到清晰的焊接同轴图像, 在激光焊接头一侧加入一个绿色光的LED点光源, 通过调整LED点光源照射角度可以实现加大焊接区域亮度, 使得采集的图像质量最优。

In this paper, an on-line coaxial monitoring system with an auxiliary illuminant was built for fiber laser welding; the monitoring of the welding quality when butt-welding the galvanized steel was studied. First, the spectrum of the plasma produced while welding the galvanized steel was captured with the spectrometer, the spectrum of highest intensity was observed at the wavelength ranging from 430 nm to 480 nm and 620 nm to 650 nm, so a green light filter lens (central wavelength is 532 nm) was used in the light-filtering system to reduce the interference of the plasma to the monitoring of the welding quality; second, in order to get images of better quality, a green LED spot light, which was mounted beside the laser head with its incident angle adjustable, was used to increase the light intensity of the weld zone.