马口铁激光焊接质量的实时光-声监测

针对激光小孔效应焊过程中等离子体辐射出特征光并伴随特征声的现象,提出了采用光声信号联合实时监测激光焊接质量的方案.分析了等离子体辐射光谱和等离子体波声谱,研究了待征光、声信号的变化规律,发现光、声信号强度与工艺参数及焊接质量间有良好的对应关系.据此研制成光-声联合监测试验装置,可用于马口铁激光焊接的实时监测.

Optic-Acoustic Real-Time Monitoring for Laser-Welded Tinplate

A quality monitoring system has been developed for laser-welded tinplate using specific optic and acoustic signals generated by the plasma during "keyhole" welding. Experimental investigation and theoretical analysis show that both the intensity of plasma emission at wavelengths between 4 000-4 400 nm corresponding to the line spectra of excited iron atoms and ions and the pressure of plasma ionic sound wave in a frequency range of 5kHz-20kHz are dependent on the vaporization of the welded metal. Hence there must be a fairly good correlation among the intensity of the specific optic-acoustic signals, the laser parameters and the welding quality. The real-time quality monitoring system developed is found to be capable of seeing if the seam is in normal condition or there exist defects such as incomplete fusion or burn-through in it.