AC DC TIG Welders
Alternating AC current is mandatory when welding aluminium. During the reverse polarity stage, the positive half cycle provides a "cleaning" action, that is to say as electrons travel from the work piece to the tungsten electrode a process called ionic bombardment removes the aluminium oxide layer. During the straight polarity cycle, the negative half cycle provides penetration as electrons travel to the workpiece from the tungsten tip and bring heat with them. Inverter IGBT machines set the standard for AC TIG welding and you will find this technology used throughout all Metalmaster® AC/DC TIG welder machines.
