Metal parts casting 1

[Rictoven]

Hello all,
I am new here and seek much advice on my endeavors. Thank you in advance for your time.
In brief, I am considering making a mold to cast some small machine parts. I think ceramic may be the best choice for the mold. I need advise on how to make a small mold for the parts, where to obtain materials and so on. I can make the forms I wish to cast but I would like to make a reusable high temp mold with limited expansion/contraction characteristics.

I have read some articles on how it is done but most were commercial use and often ambiguous.
My questions are as follows:

Could someone recommend a place to obtain ceramic mold making materials for metal casting. Please.
Searching online results in a great many pottery making sites and I dont know anything about that either.

When using ceramic powders to make a mold, is it necessary to kiln fire the ceramic mold?
I have read about molds being made by repetitive dipping into a slurry but there was no mention if firing with the exception of burning out the plastic form used inside.

Why is ceramic mold casting for metal parts usually done in a mold which must be destroyed to free the casting?

Can a simple, high temp, precision ceramic mold be made to separate and be used again?

If not, is it because the metal makes such a bond with ceramic that it can not be freed otherwise?

If it can be made, What separation agent might one coat the surface of the mold with to facilitate removal of the casting?

Thank you for any advice offered

 

[Ceramicguy]

Try contacting Aremco Products

http://www.aremco.com

or Cotronics

http://www.cotronics.com

. Both are located in New York. Both offer small quantity castable materials suitable for experimentation. Talk to them about your application requirements and selection of most suitable material. Answers to have ready include but are not limited to metal type, atmosphere, pour temperature, mold preheat and the like. Remember you are dealing with brittle materials with tendencies toward thermal shock and sudden catastrophic failure. Make sure you are adequately protected from hot metal splash etc.

Bruce

http://www.accuratus.com

 

[Rictoven]

Thank you for your assistance. The links look like they have the information I have been looking for. And the information you included is welcome.

 

[unclesyd]

As mentioned above you give no reference to the material you want to cast. Semi-permanent ceramic molds are only used for low melting alloys like Lead and Bismith aloys. Even then you take your chances each time you use it.

Depending on you material requirement and the complexity of your part you could use something like the shell molding process to make your parts. After the initial cost the cost per shell mold is relatively cheap and requires only baking the shell, no firing.

They do use permanent metal molds for injection molding or die casting other alloys mainly Aluminum based. Here you are talking many, many dollars.

 

[Rictoven]

Thank you.

 

[unclesyd]

Stay away from Aluminum.
I personally would checkout the model steam engine sites on the Internet and purchase a set of rough castings for whatever type engine you desired.
A lot of people machine the components from cast irons that
can be purchased in all sizes and quantities. The same holds true for brass or bronze.