利用快速傅里叶分析手段对激光焊接稳定过程及出现未焊透缺陷时等离子体的光声信号进行频域分析, 发现在焊接过程稳定时, 信号的频谱中存在明显线谱, 以300 Hz处为最强。在出现未焊透缺陷时, 光声信号的频谱为连续谱, 无明显线谱。这为提高缺陷监测精度提供了一条新途径。

The spectra of the optical and acoustic signals emitted by a plasma during laser welding were studied through fast Fourier transformation. It was found that when the laser welding process was stable there existed obviouse line spectra in both optical and acoustic signals at 300 Hz. When poor penetration appeared, the spectra of them were dominantly continuous. These results provided a new way to increase the defect monitoring accuracy.