ELECTRODE FOR PLASMA WORKING Russian patent published in 2001 - IPC

FIELD: equipment for plasma arc processes: cutting, welding, plasma arc spraying, surfacing, thermal and thermochemical surface treatment, etc., applicable in construction of plasmatron. SUBSTANCE: the electrode for plasma working has a holder, an insert built in the holder and made of an emission core, and a shell enveloping the holder, the insert core is made of an alloy of zirconium and hafnium with the content of hafnium in the alloy within 0.5 to 80 mass percent. At a content of hafnium within 0.5 to 10 mass percent in the core material the shell is made of copper, at a content of hafnium above 10 to 50 mass percent in the core material the shell is made of zirconium bronze, and at a content of hafnium above 50 up to 80 mass percent in the core material - of chromzirconium bronze. The core and the shell are joined in a bimetal insert by means of joint hot pressing after their separate cold strain. Besides, the core material may additionally contain niobium within 0.2 to 0.5 mass percent. The insert is made at a relation of the shell outside diameter and the core outside diameter within 1.25 to 12.5. The electrode of the described construction provides for average more than 120 switchings at a total time of arc burning for more than an hour. EFFECT: the electrode does not use extremely expensive, deficient and nontechnological materials. 6 cl, 1 dwg