Firebrick Replacement

[zagarpa]

I'm trying to find a material with similar / better thermodynamic properties than firebrick. Something that absorbs heat faster, retains it longer, and radiates more of it. This material would need to be worked / molded into a dome structure. Any thoughts would be highly appreciated!

 

[Compositepro]

Absorbs heat fast means high thermal conductivity.
Retains heat longer means high heat capacity and low thermal conductivity.
Radiates more means high emissivity and reaches and higher temperature.

You have to decide the best compromise between heating-up rapidly and retaining heat longer as these are contradictory requirements. Materials are often layered to optimize the properties.

Thermal shock resistance, thermocycling resistance, and structural properties are also considerations. Unobtainium will solve every problem, perfectly.