Re: [ATM] Microwaves and craziness

[Ian Williams <i.r.williams@bristol.ac.uk>]

Further reading:

Takasago, a Japanese company, developed a series of microwave kilns to get more even heating of specialist ceramics.  Their test kiln used three 1.5 KW magnetrons with fan type stirrers and can heat components to 1600C.  Looks like the idea of building an insulated box out of fire-brick, and lining the inside with a microwave susceptor like SiC is the way to go if there's sufficient microwave power available and the insulation is good:

http://www.takasago-inc.co.jp/eg/mw/mwave2.htm
http://www.takasago-inc.co.jp/eg/mw/mwave1.htm

Also, a guy called David Reid has tried the microwave furnace idea with a home microwave and got as far as melting small amounts of iron (~1000C) using an 850W oven:
http://home.c2i.net/metaphor/mvpage.html

In summary, he found that a mould made from "a carbon (graphite) loaded primary coat stuccoed with magnetite sand" was the best susceptor/mould combination.  He used ceramic fibre wool as the thermal insulator.  The main problem he had was that his moulds would absorb the microwaves more efficiently once they'd heated up and then thermal run-away occurred in small patches, destroying the mould.  

I'll drop David Reid an email and see if he can add anything to our discussion.

Ian
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