XMCERA | Silicon Carbide Component
▼ Silicon Carbide Component
SiC ceramics not only have excellent mechanical properties at room temperature, such as high bending strength, excellent oxidation resistance, good corrosion resistance, high wear resistance and low friction coefficient, but also high temperature mechanical properties (strength, creep resistance, etc.) are the best among known ceramic materials. Hot pressing sintering, non-pressing sintering, hot isostatic pressing sintering materials, the high temperature strength can be maintained to 1600℃, is the best high temperature strength of ceramic materials. The oxidation resistance is also the best of all non-oxide ceramics. Also known as emery.
There are two main crystal structures of sic, that is, β-SiC of cubic crystal system and -SiC of hexagonal crystal system. The basic structural units of silicon carbide crystals are interspersed SiC and CSi tetrahedra. A tetrahedron has a common edge to form a plane layer, and the vertices are connected to the next layer of tetrahedra to form a three-dimensional structure. Hundreds of variants have been found because the order of tetrahedrons can form different structures. Generally, the letters C(cubic), H(hexagonal) and R(Rhombohedron) m are used to represent the lattice type, and the number of layers contained in the unit cell is used to distinguish them. For example, nH stands for the hexagonal crystal system structure with n layers of repeating periods along the C-axis, while mR Stands for the Rhombohedron structure with M layers of repeating periods along the C-axis.
SiC ceramic component is widely used in chemical, micro-electronics, and automotive for its following advantages (see below table).
|Excellent oxide||Corrosion resistance|
|High bending strength||High temperature resistance|
Silicon carbide (SiC) components are compound products with strong covalent bond. The ionic type of Si–C bond is only about 12%. Therefore, it also has excellent mechanical properties, excellent oxidation resistance, high abrasion resistance and low friction coefficient. The biggest characteristic is the high temperature strength, the strength of ordinary ceramic materials at 1200 ~ 1400 degrees Celsius will be significantly reduced, and its bending strength at 1400 degrees Celsius is still maintained at a higher level of 500 ~600MPa, so its working temperature can reach 1600 ~ 1700 degrees Celsius. In addition, the thermal conductivity of silicon carbide ceramics is also higher, second only to beryllium oxide ceramics in ceramics, so silicon carbide parts have been widely used in high temperature bearings, bulletproof plates, nozzles, high temperature corrosion resistant parts and high temperature and high frequency range of electronic equipment parts and other fields.
The initial application of SiC is due to its ultra-rigid properties, which can be prepared into various grinding wheels, emery cloth, sandpaper and all kinds of abrades, so it is widely used in the machining industry. In the Second World War, it was found that it could also be used as a reducing agent and heating element in steelmaking, thus promoting the rapid development of SiC. SiC ceramics in petroleum, chemical industry, microelectronics, automotive, aerospace, aviation, paper, laser, mining and atomic energy and other industrial fields have obtained a wide range of applications, silicon carbide has been widely used in high temperature bearings, bulletproof plates, nozzles, high temperature corrosion resistant parts and high temperature and high frequency range of electronic equipment parts and other fields.