Re: tungsten alloys for SG electrodes?

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Original poster: "Dr. Resonance" <resonance@xxxxxxxxxx>


We carry screw-in 1/2 inch dia. tungsten electrodes.  We use 1/2 dia x 1 1/4
inch brass axial pieces with 1/2 inch thick G-10 plate for our high power
systems in the 5-15 kVA range.  Above 10 kVA we also use 1 inch dia.
tungsten electrodes for the stationary electrodes as they get more wear and
need better heat dissipation for proper quenching.

Dr. Resonance
>
> Hi all,
>
> I'm currently in the process of trying to source some rod stock
> tungsten for electrodes for an RSG. I noticed that McMaster-
> Carr has some tungsten alloy as well as tungsten carbide in
> rod form and I was wondering about the suitability of these ma-
> terials for SG electrodes for a high powered coil system. I noticed
> that the "high-density tungsten alloy" is a 90% tungsten/ 6%
> nickel/ 4% copper alloy and is machinable. It also states that
> the melting point is a mere 2012*F. Is that a misprint? Surely a
> 90% tungsten alloy would have a much higher melting point than
> that, since the melting point of pure tungsten is like 6170*F!
> Maybe that was suppose to read 2012*C instead of Farenheit?
>
> Also, how suitable would tungsten carbide be for rotary elec-
> trodes, as far as heat & electrical conductivity is concerned?
> I remember reading some of the late Marc Metlica's posts re-
> garding use of tungsten carbide for SG electrodes. He had
> easy access to tungsten carbide because of some of his tool-
> ing supplies and he really liked using the carbide for this pur-
> pose. I know that tungsten carbide is extremely hard though
> and almost impossible to machine without special diamond
> tipped cutting tools, so I would prefer to use the high density
> tungsten alloy (90/6/4 - tungsten/nickel/copper percentage)
> if possible, since it's much easier to machine and is available
> in the 3/8" to 1/2" range that I'm looking for. Any comments
> from the more metallurgicaly inclined would be welcome :^)))
>
> David Rieben
>
>
>