【摘要】 采用高速摄像仪和多通道光谱仪对CO2激光深熔焊接过程中的光致等离子体进行了实时观测和分析,在局域热力学平衡(LTE)条件下,利用多谱线斜线法计算了等离子体的温度,并定量的研究了稳定的激光深熔焊接过程中等离子体的时间特性,并分析了等离子体的振荡特性与焊接稳定性的关系及其对焊缝成形的影响。研究表明,在稳定的激光深熔焊接过程中,光致等离子体成一定频率振荡,上下起伏的振荡频率和尺寸大小波动的频率大致相符,其频率基本和焊缝表面鱼鳞纹条纹的生成频率一致。而在激光深熔焊接过程的不稳定阶段,对应的焊缝表面鱼鳞纹的生成频率和等离子体的振荡频率差异很大。更多还原

【Abstract】 The laser induced plasma during CO2 laser deep penetration welding have been studied through the real-time observation and analysis with high-speed camera and multichannel spectrometer.Under the condition of local thermodynamic equilibrium(LTE),the temperature of the plasma have been calculated using the method of multispectral diagonal lines,and then the plasma time characteristic have been quantitative studied in the stable deep penetration laser welding process.Furthermore,the relationship between plasma oscillation characteristics and welding stability and its influence on the weld formation have been researched.The results show that plasma oscillates with a certain frequency in a stable welding process.Meanwhile,the up and down frequency of plasma is consistent with its size fluctuation approximately,and the frequency of plasma is also basically in agreement with the surface stripe change of weld.In the unsteady laser deep penetration welding process,the frequency of formation of stripe and the oscillation frequency of the plasma on the surface of the corresponding weld are very different.更多还原