Alumina ceramics is a material with alumina (AL2O3) as the main body, which is used in thick film integrated circuits. Alumina porous ceramic tube have good conductivity, mechanical strength and high temperature resistance. Alumina ceramics are a versatile ceramic. Because of its superior performance, the application in modern society has become more and more extensive, meeting the needs of daily use and special performance. Alumina electrical ceramics have low dielectric constant, low dielectric loss, high dielectric strength, high volume resistivity, good flexural strength, high stability, high compressive strength, and good thermal shock resistance. It is widely used in thermostats, insulating parts, various thermal equipment, electric and electrical equipment, iron-structured buildings, shipbuilding, etc. of various small household appliances.
Classification of alumina ceramics:
High-purity alumina ceramic series: ceramic materials with an AL203 content of more than 99.9% are generally made into molten glass to replace platinum crucibles because of their sintering temperature as high as 1650-1990 ° C and transmission wavelength of 1-6MM; It can be used as a sodium lamp tube with light properties and alkali metal corrosion resistance; it can be used as an integrated circuit substrate and a high-frequency insulating material in the electronics industry.
Ordinary alumina ceramics are divided into 99 porcelain, 95 porcelain, 90 porcelain, 85 porcelain and other varieties according to the content of AL203. Sometimes those with AL203 content of 80% or 75% are also classified as ordinary alumina ceramics series. Among them, 99 alumina ceramic materials are used to make high temperature crucibles, refractory furnace tubes and special wear-resistant materials, such as ceramic bearings, ceramic seals and water valve plates; 95 alumina ceramics are mainly used for corrosion-resistant and wear-resistant parts; 85 ceramics Because part of talc is often mixed into it, the electrical properties and mechanical strength are improved, and it can be sealed with metals such as molybdenum, niobium, and tantalum, and some are used as electric vacuum devices.
