Generally, the main crystal phase of alumina ceramics is α-Al2O3.
There are different series depending on the content of Al2O3 and additives.
According to the different content of Al2O3, there are 75 alumina, 85 alumina, 95 alumina, 99 alumina, etc.
According to the difference of its main crystal phase, there are mullite, corundum-mullite and corundum;
According to the different additives, there are chromium corundum, titanium corundum and so on.
Alumina ceramic is one of the most stable chemical properties and highest mechanical strength in refractory oxides;
Alumina ceramics do not react with most molten metals, but only Mg, Ca, Zr and Ti have a reduction effect above a certain temperature.
The hot sulfuric acid can dissolve the alumina ceramics, and the hot HCl and HF also have some corrosive effect.
Alumina ceramics have the lowest vapor pressure and decomposition pressure.
Due to the excellent chemical stability of alumina ceramics, it can be widely used in acid-resistant pump impellers, pump bodies, pump covers, bushings, acid-carrying pipe linings and valves.
Alumina ceramics with an alumina content higher than 95% have excellent electrical insulation properties and low dielectric loss, and thus have a wide range of applications
in electronics and electrical appliances.
The high hardness and wear resistance of alumina ceramics have been widely used in the mechanical field, such as the manufacture of textile wear parts, knives.
Alumina ceramic spark plugs are also widely used in various engines.
Transparent alumina ceramics have good permeability to visible light and infrared rays, as well as high-temperature strength, good heat resistance, and strong corrosion resistance.
Transparent alumina ceramics can be used to manufacture high pressure sodium lamp and infrared detection window material.