Silicon carbide is an increasingly popular material across industries due to its impressive mechanical and electrical properties, particularly its low thermal expansion rate and strength characteristics. Due to this property it makes an ideal candidate for telescope mirror manufacturing.
A method for producing recrystallized silicon carbide is presented, consisting of carbothermic reduction. This process heats a die-formed body to 2000 degrees Celsius in two or more hours.
High-temperature strength
Recrystallized silicon carbide (RSiC) is an advanced technical ceramic used in high performance applications like aerospace engineering. RSiC features exceptional chemical and mechanical properties at extreme end use temperatures; its microstructure consists of interlocking plate-like grains that give it high strength, toughness, wear resistance and low thermal expansion coefficient as well as good corrosion resistance properties. It is highly durable.
There are various methods for producing dense SiC ceramics, including recrystallization, reaction sintering, liquid phase sintering, hot pressing and hot isostatic sintering. Although some of these processes use sintering aids that degrade purity of ceramics, all methods produce dense ceramics with excellent thermal performance across a broad temperature range.
SiC stands out from traditional refractory materials by having high temperature strength and resistance that increases its durability in harsh environments, making it perfect for use in ceramic industry applications. Due to its superior strength and oxidation resistance, dense SiC ceramic is preferred choice for use as kiln furniture and gas burner media as well as diesel particulate filters; furthermore it can even be found in high performance ballistic armor for protection against both current and emerging threats.
High-temperature resistance
Recrystallized silicon carbide (RSiC) is an advanced high-temperature refractory ceramic material with superior thermal shock resistance properties. As such, RSiC can be found in applications as diverse as gas burners, diesel particulate filters, thermal exchangers and thermal exchangers. With exceptional chemical and oxidation resistance as well as stiffness that resists thermal expansion/contraction fluctuations it offers numerous industrial uses that RSiC excels.
In addition to being an extremely durable material, RSiC boasts outstanding room temperature strength. It can be easily formed into complex shapes while resisting flame erosion and slag attack as well as being resistant to abrasion and bending – it even acts as an electrical insulator!
RSiC is composed of silicon carbide powder, carbon and binder material mixed together and then formed into a mold for sintered at high temperatures to produce pure RSiC material. Through this process, powder recrystallizes while the binder material dissipates leaving pure RSiC material behind.
RSiC is one of the premier materials used for high-temperature applications. Due to its stiffness and corrosion/oxidation resistance, it makes an excellent choice for kiln furniture like rods, shed boards and special-shaped parts. Furthermore, this material can also be made into porous forms with open pores that reduce weight and energy usage in addition to helping facilitate firing porcelain pieces for increased utilization in your kiln.
High-temperature conductivity
Silicon carbide boasts exceptional thermal conductivity at room temperature and offers low coefficient of expansion and acid corrosion resistance, making it a suitable material for harsh environments. Moldable into various geometric shapes, Silicon carbide can also withstand high temperatures with ease.
Material such as clay is commonly used to fabricate parts for kilns, such as saggers, shed boards and rollers, which reduce load on the kiln while increasing utilization and decreasing energy costs. Furthermore, porous forms exist so they can easily fit any contour of a kiln’s interior wall space.
RSiC stands out from its ceramic peers by being chemically pure and its ability to retain strength at high temperatures, making it an ideal material for use in semiconductor furnace components. Furthermore, its excellent chemical purity and ability to retain strength at higher temperatures make it popularly used as kiln insulator plates, paddles and wafer tray supports. Furthermore, this versatile material serves as wear-resistant structural parts in industrial high temperature kilns.
RSIC ceramic is a high-purity SiC material with a porous network structure made using an evaporation-coagulation process and fired at 2400 degC for firing. Unlike powder sintering, RSIC production does not experience shrinkage during infiltration phase; this allows very large parts to be manufactured with tight tolerances compared with powder sintering while being less expensive overall.
High-temperature oxidation resistance
Silicon carbide provides exceptional oxidation resistance at high temperatures due to its protective silica layer that prevents oxygen from reacting directly with its substrate, known as parabolic kinetics. Unfortunately, however, its process is complicated by impurities and nucleation sites like impurity additives or cations which increase viscous oxide layer formation with higher oxygen permeability; furthermore, oxidation rate depends on concentrations of cations present on its surface coating coatings.
Sintered silicon carbide oxidation can be modelled using the Deal-Grove model, which is applicable for wet and dry environments, including thin films as thin as several nanometers. Accurate kinetic data for thicknesses up to few nanometers is easily available using this approach; however, thin layers cannot be fitted with linear-parabolic curves due to insufficient data.
Pressureless sintered silicon carbide (PSSiC) is an increasingly popular material for creating nozzles and valves in the nuclear industry, often exposed to extreme conditions of high pressure and temperature abrasion and corrosion. Furthermore, PSiC can also be used as anticorrosive pipe linings with great success.
SSIC is produced from very fine powder that contains sintering additives and then processed using traditional ceramic manufacturing processes and sintered at 2,000degC for sintering. This technology enables mass production volumes at reduced costs than traditional methods.