>99.6% Alumina (Al2O3) Disc Inert to hydrogen, carbon and refractory metals; can be used at operating temperatures to 1750°C in both oxidizing and reducing atmospheres.
Heating and Cooling Instructions
Alumina is sensitive to thermal shock. Try to warm up the furnace chamber slowly. Heating rate of 150-300°C per hour is recommended for the first 1-1.5 hours to reduce the impact of thermal shock.
Lower the temperature as gradually as possible. Cooling down rate is often half of the heating rate (75-150°C per hour). If possible, arrange for consecutive heating of furnace to maintain a hot crucible. If taking the crucibles out of furnace into room temperature to pour the melted material, try to make the process as gradual as possible.