喷嘴结构对微等离子弧输出特性影响的数值仿真与验证  

Numerical and Experimental Study of Micro-plasma Arc Behavior with Different Nozzle Structure

作　　者：刘佳[1] 戴伟[1] 郑志镇[1] 李建军[1] 

机构地区：[1]华中科技大学材料成形与模具技术国家重点实验室,武汉430074

出　　处：《中国表面工程》2017年第3期122-130,共9页China Surface Engineering

基　　金：国家科技重大专项(2012ZX04010-081)~~

摘　　要：通过数值模拟和试验研究相结合的方法,在考虑微等离子喷枪喷嘴结构的条件下,建立了大气压下脉冲放电微等离子弧的数值模型,重点研究了喷嘴孔径、喷嘴工件距、阴极内缩量以及电流大小对微等离子弧的影响,并通过光谱仪来表征微等离子弧作用的温度分布。结果表明:喷嘴结构对微等离子弧的形成与稳定有重要影响:在有效压缩距离点内,喷嘴孔径的减小以及喷嘴工件距离的缩近才对工件温度的提高有显著影响;一定范围内,工件的温度随电流的增大而增大;阴极内缩量对工件的温度影响不大。微等离子弧温度场的数值模拟结果与光谱仪测量结果基本一致,验证了模型的可靠性。A finite element model of pulsed discharge micro-plasma arc （MPA） under atmospheric pressure was established based on combination of numerical simulation and experimental study. The influence of nozzle structure, diameter, nozzle distance, shrinkage of the cathode and the current size on the MPA were mainly discussed. The spectrometer was used to characterize the MPA temperature distribution. The results show that the nozzle structure has an important effect on the formation and stability of the MPA. In the effective compression distance, the nozzle diameter decreases and the nozzle distance from the workpiece has noticeable impact on the temperature increase of the workpiece. In a certain range, a larger current brings a higher workpiece temperature, while the cathode shrinkage has little effect on the workpiece temperature. The experimental results show that the numerical simulation results of MPA are in good agreement with spectrometer measurement.

关 键 词：微等离子弧 数值模拟 喷嘴结构 有效压缩距离 

分 类 号：TG456.2[金属学及工艺—焊接]