Development and application of alumina ceramics
Alumina ceramics have high mechanical strength, large insulation resistance, high hardness, wear resistance, corrosion resistance and high temperature resistance and a series of excellent properties, which are widely used in ceramics, textile, petroleum, chemical, construction and electronics and other industries, is the most widely used oxide ceramics, the largest production and sales of ceramic new materials.
Usually alumina ceramics are divided into two categories: one is high aluminum porcelain, the other is corundum porcelain. High-aluminum porcelain is a ceramic with Al2O3 and SiO2 as the main components, in which the content of Al2O3 is more than 45%, with the increase of Al2O3 content, the performance indicators of high-aluminum porcelain have been improved. Because of the difference of the main crystal phase in the porcelain body, it is divided into corundum porcelain, corundum - mullite porcelain, mullite porcelain and so on. According to the different Al2O3 content, it is also known as 75 porcelain, 80 porcelain, 85 porcelain, 90 porcelain, 92 porcelain, 95 porcelain, 99 porcelain and so on. High-aluminum porcelain is widely used, in addition to the use of electric vacuum devices and device porcelain, but also a large number of thick film, film circuit board, spark plug porcelain body, textile porcelain, whisker and fiber, abrasives, abrasives and ceramic knives, high temperature structural materials. At present, the most widely used alumina ceramics produced, sold and used in the market is corundum porcelain with Al2O3 content of more than 90%.
As one of the main components of ceramic raw materials, alumina is very rich in the crust, with an average content of 15.34% in rocks, which is second only to SiO2 in nature. There are two main categories of alumina generally used in the ceramic industry, one is industrial alumina and the other is fused corundum.
Industrial alumina Industrial alumina is generally based on natural mineral bauxite with high aluminum content (the main mineral composition is aluminum hydroxide, such as hydrodiaspore (xAl2O3 ·H2O>, diaspore, diaspore and other alumina hydrate composition >) and kaolin as raw materials, through chemical method (mainly alkali method, The use of Bayer method - alkali lime method > treatment, remove impurities such as silicon, iron, titanium to prepare aluminum hydroxide, and then calcined, the majority of its mineral composition is γ-Al2O3. Industrial alumina is a white loose crystalline powder, and the particles are porous spherical aggregates composed of many γ-Al2O3 crystals with a particle size < 0.1 μm, with a porosity of about 30% and an average particle size of 40 ~ 70μm.
FOUNTYL TECHNOLOGIES PTE. LTD. was located in Singapore, we are focus on the research and development, manufacturing and technical services of precision ceramic parts in the semiconductor field for more than 10 years. our main product are ceramic chuck, ceramic end effector, ceramic plunger and ceramic square beam, and produces various of ceramics (porous ceramics, alumina, zirconia, silicon nitride, silicon carbide, aluminum nitride and microwave dielectric ceramics and other advanced ceramic) parts.