Tiny Induction melting furnace

Earlier, you said

"Absolutely...mind that the crucible is conductive. Moderate resistivity is best, I wouldn't go with ferromagnetic materials personally. Something like titanium would be good. Maybe 300 series annealed stainless."

If the crucible is now changed to an insulator, how does it get hot from induction?

Mike Monett

:blink:

I changed the subject. :-p

For the application the thread needs (heating something nonconductive), you need a susceptor. Might as well be the crucible, so make it something nonreactive and conductive (like graphite or titanium).

Metal melting on the other hand has greater need of a refractory crucible, especially since the metal is a good enough susceptor on its own. ;-)

Tim

-- "California is the breakfast state: fruits, nuts and flakes." Website:

OK, I found your original post in google:

"Induction heating (to about 300 C) would be elegant because it would permit easy transfer of the crucible into and out of the chamber wihout having to bother about electrical or thermal contacts for resistive heating."

That makes sense - trying to get reliable contacts at high temperature might be a problem.

However, your temperature is quite reasonable. How about a small heating coil around the crucible?

And the next problem - regardless of the heating method used, how do you monitor the temperature in order to control the heater?

Mike Monett

Yes. It has been given in my original post but got snipped out of the quotes.

For higher power we often use electron bombardment, and we might take that route in this instance as well if inductive heating turns out to be impractical.

--Daniel

For 300degC all you need is some halogen lamps of the type used in cookers.