Plasma-arc spray gun for surfacing parts of complex form

Abstract

A plasma-arc spray gun (Fig. i) has been developed for surfacing of parts of complex configuration and also small diameter shafts with corrosion resistant materials. The gun is designed for axial delivery to the plasma arc of solid or powder wire up to 1.6 mm in diameter. The gun uses certain parts of a standard torch for argon-arc welding, which is made up of a UDG 501-1 unit (the nozzle holder i, coupling nut 2, and insulator 3). The copper plasma-forming nozzle is screwed into the nozzle holder using the thread on it. The nonconsumable copper electrode for welding with reverse polarity has a water cooling channel covered with a ring. The insulator 7 provides centering of the assembly for advance of the consumable electrode relative to the nonconsumable. The consumable electrode is advanced through the tip along the axis of the channel of the nonconsumable electrode and the nozzle. The water and argon are supplied through connections. The shaft is intended for fastening of the plasma gun to the delivery mechanism of the PDG 307 semiautomatic welding machine.