how to make and fire alumina ceramics at low temp

[gmgallag]

I know this question is below the level of expertise on this site, but I have searched for hours (google and here), and not really found anything on the basics. If you could just give me the 1, 2, 3 of how to make an alumina ceramic in my oven (~1000 F), I would be most appreciative.

So far, I have found ground alumina used for abrasive air blasting, but I assume this won't work (too corse maybe).

Also, I have found calcined alumina:

http://www.scarva.com/Models.aspx?M...gle&utm_medium=Shopping&utm_name=UnitedStates

Is this what I need? Then what? Add water (read that high concentration alumina is water insoluble?). Add some other chemical to lower the firing temperature? Throw it in the oven?

Sorry you guys, a lot of basic questions. Maybe you can point me to a good book on the subject. Any help is appreciated. This is to be used for a crude conductive heat plate, so impurities and such are fine (just so it maintains a high thermal conductivity).

Thank you much.

 

[cloa]

The firing temperature is set by the ceramic and not by additives. Additives are for forming ability mostly. Have you considered that thermal stresses which might break an impurity and crack laden plate. Is this one off- better to leave it a professional or big run?

 

[tomwalz]

Search for "Aluminum oxide plate", "synthetic Ruby", "Corundum powder"

Buy the powder and mix it with something that will set up at the desired temp but it won't have the properties of pure Alumina.

You could try massive pressure but not in a home oven. You could try laser sintering but not at home.

Maybe a low melting metal binder such as lead or zinc. Watch out for safety hazards from fumes. Again not pure alumina.

Thomas J. Walz
Carbide Processors, Inc.

http://www.carbideprocessors.com

Good engineering starts with a Grainger Catalog.

 

[gmgallag]

Thank you both. Good info. Will definitely research this more this week, though it sounds like I may need to go with some other construct. Again, I appreciate the input.

 

[Ceramicguy]

Look up the potting and casting compounds at Aremco Products.

http://www.aremco.com

. They can help you with small lot requirements.

Bruce

http://www.accuratus.com

 

[ceriously]

There is so much more to it than that! Unless you want to hire a ceramic engineer, I'd suggest just buying the plate. Or, search the archives of the American Ceramic Society Bulletin for lots of articles on the subject (but you have to be a member - or go old school if you have access to a university library).

Check out Coorstek

http://www.coorstek.com

or Rath

http://www.rath-usa.com

I'm sure there are lots of other companies out there that would be willing to help you out.

Good luck!

 

[IRstuff]

You need to specify what the intended use is; is this a bowl, or a hybrid substrate? You might want to look at low temperature co-fired ceramic (LTCC) materials and sources. However, the lowest firing temperatures I've seen are in the neighborhood of 850ºC to 880ºC

TTFN
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