Alumina ceramic is inert in pure form and is used in chemical and water applications as a mating ring for carbon-graphite primary rings. Alumina is limited to moderate speeds and pressures. Alumina is susceptible to thermal shock, and is not recommended for services involving periods of dry running or for petroleum refinery services.
AL2O3MgO>=% 99.5 97
Bend strenght(g/cm2) 3000 2800
Density (g/cm3) 3.9 3.75
Hardness(HRA) 90 87
Porosity(%) 0.5 0.5
Coefficient of heat Expansion (10-6/°C) 5.3 5.5
Thermal Conductivity (W/M.K) 16.7 15.5