What plate material which is heat resistant, non heat-conductive
What plate or container material which is heat resistant but non heat-conductive, so to preserve heat of melted metal put upon its surface?
The cheapest crucible ever is this bread made into one by AVE that actually held molten aluminum. https://www.youtube.com/watch?v=L-qOIO6IQWk
Carbon Aerogels can be made by heating bread in an inert atmosphere and baking out everything not carbon.
The two materials commonly used for crucibles are alumina ceramic and graphite.
Space-shuttle asbestos/ceramic tiles.
AeroGel.
Other Ceramics.