Zirconia ceramic block is divided into two types of high-purity and ordinary type. High purity alumina ceramics with more than 99.9% Al2O3 is generally made of molten glass to replace the platinum crucible because their sintering temperature is up to 1650-1990 ° C and their transmission wavelength of 1-6 μm.
Use of its light and alkali corrosion resistance can be used as sodium lamp; in the electronics industry can be used as integrated circuit substrate and high-frequency insulation materials. According to the different Al2O3 content, ordinary alumina ceramic is divided into 99 porcelain, 95 porcelain, 90 porcelain, 85 porcelain and other varieties, sometimes Al2O3 content of 80% or 75% are also classified as ordinary alumina ceramic series.
One of 99 alumina ceramic materials used in the production of high temperature crucible, refractory tube and special wear-resistant materials, such as ceramic bearings, ceramic seals and water valves, etc.; 95 alumina porcelain is mainly used as corrosion-resistant, wear-resistant components; due to the usual incorporation of some talc to improve the electrical properties and mechanical strength, with molybdenum, niobium, tantalum and other metal sealing, and some as electric vacuum device devices.