Electromagnetic Thermal Fluid Simulation Of Vacuum Arc Cathode Spot With Vapor From Oxide Layer

The vacuum arc cathode spot can be applied to pretreatment of thermal spray because it can remove oxide layer on the metal surface. However, the cathode spot affected by the oxide layer remains unclear. In this paper, the dynamics and energy balance of cathode spot affected by the vapor from the oxide layer and the metal surface were elucidated. The distribution of temperature, electromagnetic field, and velocity were calculated by the 3D electromagnetic thermal fluid simulation. As a result, the cathode spot moved to oxide layer side because the vapor from oxide layer raised the electrical conductivity near cathode surface. The vapor induced ion current to oxide layer side, and ion heating on metal surface increased.