An ac plasma arc welder of new control system

摘要

When aluminium or aluminium alloy is plasma-arc-welded, the welding is normally done while cleaning and removing the oxide film of high melting point formed on the surface. However, in the cleaning through the reversed polarity arc generation with the electrode as plus and the aluminium material as minus, the electrodes are quickly consumed, and arc stability was inadequate for automatic welding. To reduce electrode consumption in the cleaning period, we developed an AC plasma arc welding machine using a new control system to generate the reversed polarity arc necessary for the cleaning action between a water-cooled copper nozzle and aluminium material instead of between the electrode and aluminium material.