大气热喷涂等离子体射流中电子温度和电子密度的测量

Characterization of Electron Density and Temperature in Atmospheric Thermal Plasma Spray

发射光谱研究是热喷涂等离子体诊断的一种重要的方法。通过使用发射光谱测量的氩原子在763151和772142 nm处谱线辐射强度的信息,采用双谱线法计算大气热喷涂等离子体射流的电子温度,研究纯氩气条件下,不同的氩气流量和不同的弧电流对热喷涂等离子体射流中电子温度的影响。通过使用HB谱线的Stark展宽,来计算热喷涂等离子射流的电子密度,研究氢气流量变化对电子密度的影响。结果表明,电子温度随等离子体功率的增加而增加,氩气流量增加时等离子体的电子温度略有降低;对于氩-氢等离子体,氩-氢混合气体中氢气流量增加时等离子体的电子温度和电子密度都显著增加。

The electron temperature and density, from the plasma jet in atmospheric thermal plasma spraying, were experimentally characterized by evaluating the argon emission intensities at the wavelengths of 763.51 and 772.42 nm, re- spectively. The impacts of the plasma spraying conditions, such as the Ar flow rate and arc current of the plasma, on the electron temperature were evaluated. The electron density and the influence of H2 flow rate on the electron density were calculated by means of Stark broadening of the H~ spectrum. The results show that the electron temperature rose up with an increase of the plasma power,but dropped down a little with an increase of Ar flow rate. When it comes to Ar-H2 plas- ma, an increase of the H2 concentration strongly enhanced the electron temperature and density.