Alumina ceramic manufacturers

Alumina ceramic firing technology

The technical method of densifying a granular ceramic body and forming a solid material is called sintering. That is to say, the gaps between the particles in the sintered body are removed, and a small amount of gas and impurity organic matter are removed, so that the particles grow and combine with each other to form new substances.
The heating device used in firing is the most widely used electric furnace. In addition to atmospheric pressure sintering, that is, pressureless sintering, there are also hot pressing sintering and hot isostatic pressing sintering. Although continuous hot pressing sintering can increase the output, the cost of equipment and molds is too high, and the length of the product is limited due to axial heating. HIP sintering uses high-temperature and high-pressure gas as the pressure transmission medium, which has the advantage of uniform heating in all directions, and is very suitable for sintered products with complex shapes. Due to the uniform structure, the material performance is 30~50% higher than that of cold press sintering. 10-15% higher than ordinary hot pressing sintering. Therefore, some high value-added alumina ceramic products or special parts for national defense and military industry, such as ceramic bearings, mirrors, nuclear fuel, gun barrels and other products and fields, are all sintered by hot isostatic pressing.
In addition, microwave sintering method, arc plasma sintering method and self-propagating sintering technology are also under development and research.
Alumina Ceramic Manufacturer Finishing and Packaging Process
Some alumina ceramic materials require finishing after sintering. For example, products that can be used as artificial bone require high surface smoothness, such as a mirror surface, to increase lubricity. Due to the high hardness of the alumina ceramic material, it needs to be finished with a harder grinding and polishing brick material. Such as SIC, B4C or Diamond. It is usually ground step by step from coarse to fine abrasives, and finally the surface is polished. Alumina ceramic strengthening process is generally available for
alumina ceramic manufacturers.
In order to strengthen alumina ceramics and significantly improve their mechanical strength, a new process of alumina ceramic strengthening has been introduced abroad. The process is novel and simple. The technical method adopted is to coat a layer of silicon compound film on the surface of alumina ceramics by electron beam vacuum coating, sputtering vacuum coating or chemical vapor deposition, and heat the alumina ceramics at 1200 ° C ~ 1580 ° C to increase the thickness of the alumina ceramics. tough.
The mechanical strength of reinforced alumina ceramics can be greatly improved on the original basis, and ultra-high-strength alumina ceramics can be obtained.