Alumina ceramics is a kind of ceramic material with alumina (Al2O3) as the main body. Alumina ceramics is a very wear-resistant and precise ceramic material, which is widely used in all walks of life. The main moulding methods of alumina ceramic products are dry pressing, grouting, extrusion, isostatic pressing, injection and propagation. Different shapes, sizes, complex moulding and precision products need different moulding methods. Aluminum oxide ceramics sintered at high temperature can only be processed by diamond grinding process. Alumina ceramics have high hardness and wear resistance, strong corrosion resistance, high temperature corrosion resistance and biological inertia. In addition, alumina sintered at high temperature can be highly polished. Because of its sintering temperature as high as 1650-1990 (?) C and transmission wavelength of 1-6 micron, melted glass is generally made to replace platinum crucible; sodium lamp tube is made of its light transmittance and alkali corrosion resistance; and it can be used as integrated circuit substrate and high frequency insulating material in electronic industry.