Alumina (Al2O3) is a hard, chemically resistant material and has the ability to withstand very high temperatures in aggressive environments. Aluminum oxide is an electrical insulator but has a relatively high thermal conductivity for a ceramic material.
Mullite (3Al2O3 • 2SiO2) is a refractory oxide material combining low thermal expansion, good mechanical strength, and resilience at elevated temperatures. It has excellent high temperature properties with improved thermal shock and thermal stress owing to the low thermal expansion, good strength and interlocking grain structure.
