Alumina crucibles, also call corundum crucibles, usually refer to crucibles with more than 95% alumina content. They are widely used because of the good high-temperature insulation, mechanical strength, high thermal conductivity, and low thermal expansion. To better extend the service life of the alumina ceramic crucible, do you know what are the precautions?
1. Do not use a gasoline gun, acetylene gun, or alcohol torch to heat the crucible directly; it is not recommended to heat the crucible with coke or an open universal furnace.
2. Before using the crucible for the first time, put it in an oven at 105°C for 120 minutes or more to remove the water.
3. Do not heat up or cool down too fast, it is recommended that the heating speed is less than 5 Deg.C/minute for temperatures below 1200 deg. C and less than 4 Deg.C/minute for temperatures above 1200 Deg. C.
If the temperature is high, it is recommended to turn off the power directly and let the crucible cool down with the furnace, the crucible will easily crack because of the fast cooling speed in the early stage.
4. The distance between the crucible and the heat generator (e.g. silicon-carbon tube, silicon molybdenum rod, heating wire, etc.) should be greater than 2 cm.
5. The bottom of the crucible should not be in direct contact with the bottom of the furnace chamber as much as possible. It is recommended that the crucible be hollowed out with a temperature-resistant substance such as a corundum sheet to form air convection.
Ceramic Parts India Inc.CO., Ltd, we are a global ceramics manufacturer and supplier, crucibles are shipped worldwide, please visit our website for more details. www.ceramicpartsindia.com