用于大气环境中的氮等离子体枪放电特性及束流强度

Discharge Characteristics and Jet Intensity of Nitrogen Plasma Gun in Atmosphere

为将等离子体用于材料表面局部处理的研究,对自行设计的一种用于大气环境中的辉光放电氮等离子体枪的放电特性和束流强度进行了实验测量和理论分析,得出了放电伏安特性曲线和气流量对枪炬工作电压电流的影响,分析了其原因,并给出了拟合解析方程式,发现工作电压和工作电流分别与气流量成e 指数增长和e 指数衰减关系;同时得出了该等离子体枪束流先膨胀后收缩特征分布,在束流喷出5mm处达到最大作用面积,找到了得到最佳强度气流量值0 2m3/h,给出了有关的机理分析,进而得出制备样品的最佳条件·

Aiming at local treatment of material surface by plasma, a glow discharge N_2 plasma gun to be used in atmosphere was designed to investigate and analyze theoretically its discharge characteristics and jet intensity. As experimental results, the discharging volt-ampere characteristic curve and effect of jet flux on torch's working voltage/current were discussed on their causes, with an analytic curve-fitting equation given. It was found that the working voltage and current is exponentially increasing and decreasing in relation to jet flux, respectively. Furthermore, the jet from the plasma gun is characterized by expanding first then contracting, with a maximum active sectional area found 5 mm distant from torch tip. The optimal intensity gas jet is 02 m^3/h. The operation mechanism of the plasma gun was thus discussed further to find out the optimal conditions on which the specimen preparation will be available.