Nick, SiC coated is certainly interesting but I was thinking of solid carbide tools that are available and reasonably priced. Solid carbide tools are very rigid compared to coated steel tools but are easily broken. The rigidity creates larger forces on the tool during machining so that a fine dense structure of the carbide is required to avoid fracture. I've certainly broken my share of small solid carbide tools on my small NC mill.
I'm surprised that the thermocouple is reading such high temperatures. A passive mechanical meter on the thermocouple output would perhaps be less precise but might integrate the noise and be more readable at high power. Thanks for the temperature data. George ------------------------------------------------------------------ > George, > > Thats a good suggestion. Unlike the stainless or > nickel or tungsten cathodes, the SiC looked like > rather than having been corroded or burned away, it > was sort of spalled or broken apart. So once > mechanical stability is assured, (as with a mill or > drill that is hex-SiC coated) some really good > performance might be noted. > > During the TC sheath runs, the plateau temperature > given about 100 watts, and the mass of the couple, > ended up between 400 and 450C typically. (Averaged out > over LOTS of noise) Very jumpy. Toward the end of > the D2O run, I cranked the voltage up to about 75V and > as the plasma went to pinkish white, I saw some > sporadic momentary jumps up past 850C. I'm sure the > actual temperature at the plasma interface was > phantastically higher, but the temp as read by the > nested couple buried in MgO within the stainless > sheath was attenuated. > > NR > >
