축 방향 자기장애 의한 아크의 거동과 전극표면의 손상

Arc behaviors and electrode surface damage under the axial magnetic field

Axial magnetic field was applied into the hollow anode of plasma torch for the purpose of extension of electrode lifetime. The average arc voltage increased because the arc column became longer, the arc voltage ripple frequency became low. The steady state of arc voltage was removed by applied magnetic filed. The lifetime of electrode was over 1000 hours which is 100 times longer than operation without magnetic field.