直流电弧空气等离子体炬阴极材料的烧蚀研究  

Erosion of Cathode Material of DC Arc Air Plasma Torch

作　　者：孙海明[1] 刘东雨[1] 陈雅婷[1] 

机构地区：[1]华北电力大学能源动力与机械工程学院,北京102206

出　　处：《稀有金属》2012年第2期260-265,共6页Chinese Journal of Rare Metals

基　　金：国家教育部重点实验室开放基金(K 0810)资助项目

摘　　要：空气等离子发生器中阴极材料的烧蚀行为直接影响阴极寿命,阴极材料和工作环境不同是影响阴极烧蚀的重要因素。通过直流电弧空气等离子体炬切割实验,研究了两种切割电极用阴极材料(Hf和Ag)烧蚀行为,采用扫描电镜(SEM)深入分析了阴极烧蚀机制。发现在同等条件下,Hf阴极的烧蚀量和烧蚀率远低于Ag阴极,Hf阴极的抗烧蚀性能较好。随着工作时间间隔的延长,Hf阴极和Ag阴极的烧蚀率都会降低,并且在连续工作时间大于60 s后,两种阴极材料的阴极烧蚀率都逐渐趋于一定值。分析表明,阴极烧蚀量的大小主要取决于阴极液化区域的大小以及液体或气体溅射量的大小,在工作环境下,阴极的导热性和电子逸出功对阴极的烧蚀量都有着至关重要的影响。在影响阴极烧蚀性能诸因素中,阴极材料的电子逸出功占据主导地位,为主要因素;阴极材料的导热性和熔点占据次等地位,为次要因素。The erosion behavior of cathode material in plasma generator had a direct effect on cathode material lifetime,different kinds of cathode material and different working conditions had an important effect on cathode erosion.Two kinds of cathode material（hafnium and silver） were used for cutting by DC arc air plasma,the kinetics of erosion behavior and further erosion mechanism of cathode through scanning electronic microscope were studied.The results showed that under the same conditions,the erosion masses and erosion rate of hafnium cathode was much lower than silver cathode,which implied that the anti-erosion ability of hafnium cathode was better.As working time interval prolonged,the erosion rates of hafnium and silver cathodes decreased.After continuous working time more than 60 s,the cathode erosion rates of two cathode materials gradually went to a fixed value.The analysis showed that cathode erosion masses were determined by cathode liquefaction zone dimension,liquid or gas sputtering masses.Under working conditions,the thermal conductivity and electron work function of cathode materials both had a very important effect on cathode masses.In different factors of affecting on cathode erosion ability,the leading position was occupied by electron work function of cathode materials,which was the main factor;the inferiority position was occupied by thermal conductivity and melting point of cathode materials,which was subordinate factor.

关 键 词：直流电弧空气等离子体炬 阴极烧蚀 电子逸出功 熔点 导热率 

分 类 号：TG113.22[金属学及工艺—物理冶金]