Silicon carbide is formed in two ways, reaction bonding and sintering. Each forming method greatly affects the end microstructure.
Silicon Carbide (SiC)
Reaction bonded SiC is made by infiltrating compacts made of mixtures of SiC and carbon with liquid silicon. The silicon reacts with the carbon forming more SiC which bonds the initial SiC particles.
Sintered SiC is produced from pure SiC powder with non-oxide sintering aids. Conventional ceramic forming processes are used and the material is sintered in an inert atmosphere at temperatures up to 2000ºC or higher.
Both forms of silicon carbide (SiC) are highly wear resistant with good mechanical properties, including high temperature strength and thermal shock resistance. Our engineers are always available to best advise you on the strengths and weaknesses of each ceramic for your particular needs.
Typical silicon carbide applications
They are used more for operation with wear at low temperature than for high temperature behavior. SiC applications are such as sandblasting injectors, automotive water pump seals, bearings, pump components, and extrusion dies that use high hardness, abrasion resistance, and corrosion resistance of carbide of silicon.
- Fixed and moving turbine components
- Seals, bearings, pump vanes
- Ball valve parts
- Wear plates
- Kiln furniture
- Heat exchangers
- Semiconductor wafer processing equipment
For further information on our silicon carbide and how this can be used for your product, contact us today.
Silicon carbide properties
Silicon carbide (SiC), also known as carborundum, is a semiconductor containing silicon and carbon.
The crystal structure of the SiC ceramic wear-resistant pipe is similar to that of the diamond tetrahedral structure. It is a compound composed mainly of covalent bonds. Its hardness is high (Mohs 9.3), its performance is stable, and its physical properties are similar to diamond. It is also known as emery. Black silicon carbide crystal Hardness is the second-order material for diamonds. It is mainly used for making abrasives and grinding wheels, and partly for the production of silicon carbide ceramics.
The characteristics of the elastic modulus and thermal expansion are given by the characteristics of the SiC crystal itself, and the thermal conductivity or thermal diffusivity of the silicon carbides tends to be substantially higher than those of the other structural ceramics. The combination of a high elastic modulus and moderate coefficient of thermal expansion makes the SiC susceptible to thermal shock damage. The resistance to thermal shock is significantly lower than that of silicon nitride, but higher than the structural zirconia ceramic. The behavior before thermal shock is also very dependent on the application. For example, very rapid temperature changes can lead to a preference for Si3N4 over SiC, while for moderate rates of temperature change the high thermal conductivity of SiC can lead to better performance.
Typical silicon carbide characteristics include
- Low density
- High strength
- Good high temperature strength (Reaction bonded)
- Oxidation resistance (Reaction bonded)
- Excellent thermal shock resistance
- High hardness and wear resistance
- Excellent chemical resistance
- Low thermal expansion and high thermal conductivity
New multiphase silicon carbide ceramics
The new multi-phase silicon carbide ceramic is made of silicon carbide as the main raw material, through reasonable particle assembly, adding silicon powder, alumina powder and binder, and then kneading, molding, drying and high-temperature sintering. It has excellent properties such as high hardness, good wear resistance, thermal stability and chemical corrosion resistance, especially it is insensitive to abrasive angle of attack. The new multi-phase silicon carbide ceramic is affixed as an lining material or embedded in the surface of related equipment, which can greatly improve the wear and corrosion life of the equipment. The abrasion resistance of the wear-resistant particles is three times that of alumina (corundum) ceramics and five times that of high-alloy wear-resistant cast steel. Therefore, it is widely used in thermal power, coal, mining, metallurgy, chemical, cement, port and other fields, and is currently a cost-effective wear-resistant material.
Reinforced silicon carbide ceramic composite pipe
Structure: Silicon carbide ceramics are lined in ordinary carbon steel pipes to form silicon carbide/steel composite pipes. The inner lining silicon carbide adopts the unequal thickness eccentric circular structure type, that is, the outer side of the curved pipe and the lower half of the straight pipe are slightly thicker, so that the wear life of each part of the pipe is the same, and the waste is reduced. The outer side of the silicon carbide is wrapped with FRP to increase the overall strength level. The transition section can be made of ordinary carbon steel pipe or oxygen-aluminum composite wear-resistant steel pipe or flanged according to user requirements. Can be made into a straight tube or a shrimp waist bend.
Scope of application: Low-impact and strong abrasive wear such as conveying powder, block material and ash residue working at 450 °C and 1.0 Mpa.
Performance characteristics: The comprehensive performance is good, the silicon carbide ceramic has a very high wear resistance, and has certain impact resistance and adhesion performance after the outer glass fiber reinforced plastic. The use of steel pipe as the outer casing not only improves the mechanical strength and impact resistance of the pipe, but also facilitates installation and welding. The service life of the product is 3-5 times that of alloy cast steel pipe, cast stone pipe and alumina ceramic composite pipe, generally up to 60,000 hours, and has a very high performance price ratio.
Working condition of silicon carbide ceramic wear-resistant pipe
Metallurgy and power industry:
The reason why these two industries are put together is mainly because the two industries have a large number of metal pipes for the transmission of coal powder, ash, mud, and the like. After using the wear-resistant elbow pipe, the advantages of strong wear resistance, long life and easy installation are immediately highlighted.
Mining industry:
If the wear-resistant elbow pipe is not used, the ordinary pipe is used for the transportation of the ore powder. Due to the filling of the mine and the transportation of the concentrate powder, the wear of the pipe is relatively large, so that the life of these pipes is only about one year. After wearing elbow pipes, the life of such pipes will be extended by a factor of five.
Coal industry:
If long-distance wet transport of coal is required, the pipe has the requirements of good wear resistance and high corrosion resistance, and the pipe with wear-resistant elbow can meet these requirements well.
Features
Silicon carbide ceramic pipe is made of silicon carbide as the main raw material, adding a variety of chemical wear-resistant raw materials and antioxidants, effectively improving the wear resistance of the product to Si0. A high-performance silicon carbide product that is fired at a high temperature by making a high-temperature bonded phase.
Has the following characteristics:
- Stable size, deformation resistance and high temperature strength at high temperature;
- Resistance to thermal shock, abrasion and corrosion;
- Anti-oxidation, erosion resistance.