What are the main components of alumina ceramics?

Main components of alumina ceramics

Alumina ceramic is a kind of ceramic material based on alumina, which is used in thick film integrated circuits. Alumina ceramics have good conductivity, mechanical strength and high temperature resistance. It should be noted that ultrasonic washing is required. Alumina ceramic is a kind of widely used ceramics, because of its superior performance, it has been more and more widely used in modern society to meet the needs of daily performance.

Alumina ceramics can be divided into high-purity type and ordinary type.

High purity alumina ceramic is a kind of ceramic material with more than 99.9% alumina content. Because of its sintering temperature as high as 1650-1990 ℃ and transmission wavelength of 1-6 μ m, it is generally made into molten glass to replace platinum crucible. It can be used as sodium lamp tube by its light transmittance and alkali metal corrosion resistance. It can be used as integrated circuit substrate and high frequency insulating material in electronic industry.

Ordinary alumina ceramics can be divided into 99 porcelain, 95 porcelain, 90 porcelain and 85 porcelain according to the content of alumina. Sometimes those with 80% or 75% of alumina can also be classified as ordinary alumina ceramics. Among them, 99 alumina ceramic materials are used to make high temperature crucible and refractory furnace tube materials, such as ceramic bearings, ceramic seals and water valve pieces; 95 alumina ceramic materials are mainly used as corrosion-resistant parts; 85 ceramics are often mixed with some talc to improve electrical performance and mechanical strength, and can be sealed with molybdenum, niobium, tantalum and other metals, and some can be used as electric vacuum devices.

The forming methods of alumina ceramic products include dry pressing, grouting, extrusion, cold isostatic pressing, injection, tape casting, hot pressing and hot isostatic pressing. In recent years, domestic and foreign molding technology has been developed, including pressure filtration molding, direct solidification casting, gelcasting, centrifugal casting and solid free molding. Different product shape, size, complex modeling and precision products need different molding methods.