Silicon carbide stands up well against corrosion, abrasion and erosion; makes powerful abrasives; can withstand high temperatures found in chemical plants and paper mills; makes an impressive abrasive; is resistant to wear in pipe systems – an outstanding material choice overall!
The present invention relates to a siliconized silicacarbide material characterized by its alpha (a-SiC) or beta (b-SiC) silicon carbide matrix with open porosity that contains silicon; whereby silicon fills its pores to form a composite having less than 4 vol % final porosity.
High Temperature Resistance
Silicon carbide is an extremely tough material. Able to withstand high temperatures while remaining structurally sound, it makes an ideal material choice for environments which demand resistance against extreme heat. Furthermore, silicon carbide can withstand electrical field voltages approximately ten times higher than silicon.
Silicon Carbide’s high strength and low density make it an ideal ceramic material for use in chemical plants, mills, expanders and nozzles. It excels in resisting corrosion, abrasion and erosion as well as frictional wear while boasting an outstanding Young’s modulus of over 400GPa as well as exceptional resistance against acids and lyes.
SiC atomic lattice consists of bonds between carbon and silicon atoms in an interlocked structure that gives this material its hardness and mechanical strength, as well as other properties such as low density, high elastic modulus, inertness, excellent thermal conductivity and reduced thermal expansion.
Silicon carbide’s impressive durability belies its ability to quickly absorb energy and transmit it, making it ideal for applications like radio frequency technology that requires fast switching speeds with minimal power loss and smaller devices while offering similar performance.
High Strength
Silicon carbide possesses exceptional strength, hardness and thermal shock resistance properties. As a non-corrosive material it can withstand temperatures up to 1600degC without degrading and boasts excellent impact strength and bending resistance making it suitable for load bearing applications.
Silicon carbide differs from silicon in that its atoms form four bonds instead of two, making the material much stronger than its silicon-based counterpart and capable of withstanding nearly ten times as much electric field. Furthermore, it features high heat resistance and low thermal expansion coefficient making it an ideal material to use across a range of industrial applications.
Silicon carbide’s chemical makeup of four carbon and silicon atoms arranged into four tetrahedra produces an extremely dense structure. As an extremely durable material, silicon carbide stands up to high temperatures, molten salts and acids without breaking down or dissolving.
Silicon carbide can be made through several processes, including reaction bonding and sintering, with each method altering its microstructure in its final form. Reaction bonded SiC is formed by infiltrating compacts of mixtures of silicon and carbon with liquid silicon, which reacts with carbon to form more SiC before being sintered under inert conditions to form more of this substance. Among them, Wurtzite crystal structure forms form alpha SiC (a-SiC), while cubic beta modification b-SiC exists among those techniques for producing SiC.
High Stiffness
Silicon carbide’s stiffness is an integral component in designing structural components. A high specific stiffness is highly desirable because it can reduce weight while increasing strength of structures.
Silicon carbide’s exceptional stiffness can be attributed to its unique tetrahedral crystal structure, in which each silicon atom forms strong covalent bonds with four other silicon atoms forming an interlocked hexagonal grid of bonds between itself and four others forming its crystal framework. This same structure accounts for its incredible hardness.
Silicon carbide is one of the lightest and strongest advanced ceramic materials, boasting a fracture toughness rating of 6.8 MPa m0.5 that makes it difficult for cracking to occur. Flexural strength of 490 MPa and an extremely high Young’s modulus rating of 440 GPa demonstrate its resilience under stress.
Silicon carbide stands out among other materials due to its low thermal expansion coefficient and durability in challenging environments, making it suitable for gas turbines and rocket nozzles as well as other demanding applications like high temperature/high pressure combinations without degradation. Silicon carbide stiffness depends on purity, polycrystalline type, process of formation as well as grade selection; selecting the ideal grade of silicon carbide can enhance specific stiffness while decreasing mass density by adding B4C which increases Young’s modulus while simultaneously decreasing mass density.
Low Thermal Conductivity
Silicon carbide is a hard material with a 6.8 MPa m0.5 fracture toughness rating, demonstrating its resistance to crack propagation. Furthermore, its Young’s modulus of 440 GPa confirms its stiffness – placing it amongst only diamond and boron carbide as being harder.
Silicon carbide’s electrical properties surpass those of its commercially available alternatives, with its breakdown voltage being approximately 600V compared with that of silicon. Silicon carbide may even reach 10 times greater.
SiC is distinguished by excellent oxidation resistance, thermal shock resistance, hardness, chemical stability and polycrystalline form production; either as monocrystalline ceramic (a-SiC) or polycrystalline form production with the latter employing cubic zinc blende structure featuring tetrahedral coordination of silicon atoms similar to Wurtzite crystal structure.
Silicon carbide can be produced two ways: through reaction bonding or sintering. Each method produces distinct microstructures; reaction bonded silicon carbide typically has an uneven microstructure composed of coarse particles partially connected to its matrix, leading to lower volume fraction and poor thermal conductivity than compacted microstructures with higher volume fraction of SiC content and better thermal conductivity produced through sintering.
English 
Swedish