Re: Inside A Plasma Cutter (Must See Pictures for SSTCers!)

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: FIFTYGUY-at-aol-dot-com 

In a message dated 6/12/04 1:02:46 PM Eastern Daylight Time, tesla-at-pupman-dot-com
writes:

 > A full history of torch heads for plasma cutters:
 >  http://www.hypertherm-dot-com/technology/plasma_history.htm#Conventional%
 > 20plasma%20arc%20cutting%20(1957)

     Actually, there is something on that site that might be pertinent to
SGTCs.

     "The biggest problem with air cutting has always been the rapid erosion
of the plasma torch electrode. Special electrodes, made of zirconium, hafnium,
or hafnium alloy, were needed since tungsten eroded in seconds if the cutting
gas contained oxygen. Even with these special materials, electrode life using
air plasma was much less than the electrode life associated with conventional
[inert gas] plasma."

     Anybody use zirconium or hafnium alloy electrodes in their spark gaps?
     Kinda surprises me, given the pyrotechnic uses for zirconium metal.

-Phil LaBudde