Welding plasma transfer arc

A PTA torch consists of an electrode in the center surrounded by a double-walled tube that carries the powdered metal. Argon gas passes through this annulus while metal powder is metered through the holes in the inside wall of the tube. Both exit onto the work piece through an arc struck between the electrode and the work piece see Fig. 8.118. Argon gas is circulated around the welding zone to provide a shield around the arc region. 

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Starweld, Plasma-transferred arc welding equipment, StelUte Coatings... 

Plasma Arc Welding. In the transferred-arc mode of the PAW process, shown in Figure lc, the arc is between a nonconsumable electrode and the base metal, in a manner similar to the GTAW process. The unique feature is the flow of inert gas around the electrode and through a restricted orifice, which constricts the arc to form a plasma jet. A second, outer stream of shielding gas protects the molten metal from atmospheric contamination. In the nontransferred arc mode of the PAW process, the arc is between the electrode and the constricting orifice. This mode is used for plasma spraying... 

Y. F. Hsu and B. Rubinsky, Two-Dimensional Heat Transfer Study on the Keyhole Plasma Arc Welding Process, Int. J. Heat Mass Transfer, 31, pp. 1409-1421,1988. 

Metal-to-metal wear tests of these materials were described by McCandles and Maddy [22]. Welding techniques for applying these materials are tungsten inert gas (TIG), transferred arc plasma, and oxyacetylene. 

Plasma arc welding and cutting can be of either the transferred or non-transferred arc type. The arc is struck between a non-consumed centre electrode and an annular tube surrounding it through which the gas is emitted. In the transferred arc process, which is applicable only to con-... 

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