激光深熔焊接等离子体温度光谱测量对比

Comparison of Spectrometric Measurements of Plasma Temperature in Laser Penetration Welding

采用光谱仪探测CO_(2)激光深熔焊接等离子体及光纤激光焊接羽辉的光谱信号,分别利用波尔兹曼图法和相对强度法计算获取CO_(2)激光焊接等离子体的温度,并以较优的一种方法计算光纤激光羽辉温度。结果发现,对于同一个等离子体,采用相对强度法时,选择不同谱线获得的等离子体温度差异很大;当采用波尔兹曼图法时,使用不同谱线组合获得的等离子体温度非常接近。通过对两种方法获得结果的分析,认为采用波尔兹曼图法计算得到的等离子体温度精度更高,更具有可比性。而后采用波尔兹曼图法计算羽辉温度,发现光纤激光焊接羽辉辐射的谱线中连续谱强度不可忽略,与等离子体温度的计算略有不同。

The spectrum of the CO_(2) laser deep penetration welding plasma and fiber laser welding plume is recorded by using a spectrometer.Both the relative intensity method and the Boltzmann plot method are used to calculate the plasma temperature.The results show that,for the same plasma,very different temperatures are figured out with relative intensity method,when different peaks are chosen.However,the calculated plasma temperatures are very similar with Boltzmann plot method when different spectrum peaks are used.Comparison of the results indicates that the measured temperature is more accurate and reliable with the Boltzmann plot method.Then Boltzmann diagram method is used to calculate the plume temperature,and it is found out that the continuous spectrum intensity of the fiber laser welding plume radiation line cannot be ignored,which is slightly different from the calculation of the plasma temperature.