基于光谱分析的CO_2激光+脉冲GMAW复合焊峰值状态激光能量传输研究

在激光+脉冲GMAW复合焊接过程中,焊丝端部金属熔化产生大量的金属蒸汽,导致等离子体中电子、粒子的扩散现象加剧,使得激光的传输模式和工件对激光能量的吸收率和吸收模式发生变化。基于光谱分析的方法得到了复合焊接峰值状态的电子密度和温度分布,通过高速摄影分析了不同焊接模式下等离子体形态的变化,结合Beer-Lambert吸收定律计算了不同焊接模式下激光的吸收率。结果表明,在复合焊过程中,由于焊丝端部金属被熔化,焊丝的金属蒸汽进入激光等离子体内部,导致激光匙孔上方电子密度进一步提高,等离子体吸收激光能量能力增强,使得激光的传输效率从纯激光焊的94.16%降低到了CO_2激光+脉冲GMAW复合焊的85.84%。

Study of the Laser Absorption Characteristics of CO2 Laser-Pulsed GMAW Hybrid Welding Based on Spectral Diagnosis Technique

During the process of laser‐arc hybrid welding ,the metal vapor from the wire end has great influence on the electron number and the particles in the plasma ,which changes the absorption of the laser irradiation and the energy input to workpiece . In this paper ,an optical emission spectroscopy system was employed to estimate plasma temperature and the electron number densities distribution .A high speed camera was used to analyze the plasma shape behavior .By using the Beer‐Lambert law ,the laser absorption rate under different welding mode was calculated .The result shows that the metal vapor from the wire tip lead the electron density increase ,and it make the laser energy absorption rates decreased .