Reply To: Steel and CO2.

[willit]

have you checked out http://www.cmwinc.com/tungsten-copper.php#elk100w they seem to have a multitude of alloy materials that could fit your bill. Elkonite material in (your selection) may prove to be an adequate substitute to pure tungsten considering the tungsten is then just electrically connected to a copper plate via press fit. it might fit the budget or lack thereof better also.
if the particles of alloyed material i.e. coarse tungsten granule’s are present the copper could be acid etched back to expose more of the tungsten allowing for a rough microscopic surface of sharp tungsten points within the edge of the ground teeth.
remember to retain your press fit. dissimilar metals all have dissimilar thermal expansion and can shrink or expand over time. once pressed in or chilled and dropped in pin it in place or provide a groove on the outside of the ring to provide a modicum of retention should it loosen up.