Silicon carbide (SiC) is an exceptional ceramic with impressive physical, thermal and chemical properties. Due to its exceptional physical, thermal, and chemical characteristics as well as its robust strength and durability features it has become an extremely popular engineering material.
Industrial SiC can withstand corrosion, abrasion and erosion with equal ease as high temperatures. Depending on its formation method, its final microstructure could vary significantly between sintered and reaction bonded forms of SiC.
High-Temperature Strength
Silicon carbide ceramics’ high temperature strength enables them to withstand harsh environments for extended periods, making them one of the primary materials used in aerospace and automobile engines for components like burner nozzles, jet tubes and liners. Their durability also means that they resist abrasion, corrosion, erosion as well as high-temperature creep and thermal shock shockwaves – qualities which enable them to serve aerospace engines for components such as burner nozzles.
Silicon carbide boasts the second-hardest hardness after diamond and cubic boron nitride, making it an attractive material for hard armour ballistic protection. The black-grey ceramic’s ability to reliably stop bullet penetration while offering lower product weight than armoured steel makes it a valuable component in vehicles.
Silicon carbide’s abrasion resistance makes it an invaluable material in manufacturing processes, helping reduce wear. This high-temperature ceramic can be found lining rotary and tunnel kilns as high-temperature lining material in order to prevent damage to furniture within them, as well as being used in grinding wheels and cutting tools in the abrasive industry. Furthermore, its low density and elastic modulus make SiC an excellent candidate for use as foam ceramic filtration systems that remove nonmetallic inclusions while purifying metal solution in casting plants.
Low Thermal Expansion Coefficient
Silicon carbide features an exceptionally low thermal expansion coefficient, making it a highly stable material at high temperatures. This low expansion rate can be attributed to its crystal lattice structure consisting of strong bonds between carbon tetrahedrons and silicon atoms that keeps expansion to an absolute minimum.
Silicon carbide ceramic is widely utilized for applications requiring thermal and mechanical efficiency, such as corrosion-resistant parts such as mechanical seals and pump components, as well as for abrasives, refractories, and ceramics.
Silicon carbide offers a broad selection of mechanical properties, such as fracture toughness and Young’s Modulus (a measure of material stiffness that measures its resistance to crack propagation). Silicon carbide’s fracture toughness stands out at 6.8 MPa m0.5 while its Young’s Modulus stands out at an outstanding 440 GPa; both figures place silicon carbide among the strongest materials known today, boasting superior flexural strength and creep resistance as well. Only diamond and boron carbide come close when it comes to hardness!
High Resistance to Corrosion
Corrosion resistance is an integral feature of ceramic materials, helping them withstand chemical environments with greater ease, thereby lowering maintenance costs and increasing safety. Silicon carbide stands out as one of the most corrosion resistant materials available, offering exceptional resistance against acids, steam and high temperatures; providing exceptional protection from wear-and-tear, making it suitable for mechanical seals bearings and dynamic components within petrochemical industries.
Silicon carbide crystallizes into an indented close-packed structure made up of covalently bound silicon and carbon atoms arranged in close-packed arrangements known as Polytypes, with four Si atoms in two primary coordination tetrahedra made of four Si and four C atoms arranged into two primary coordination tetrahedra each consisting of four Si atoms and four C atoms forming eight-sided hexagonal arrangements known as Wurtzites or Wurtzites which create over 200 different Polytypes out of which cubic b-SiC is more commonly encountered compared with Wurtzite or Wurtzite’s hexagonal hexagonal Wurtzite crystal structures which contain over 200 variants with no cubic structure having more than 200 different configurations being present within these crystal structures polar structures known as Wurtzites having more than 200 such variants known to date with cubic b-SiC being most popular among these among other crystal structures containing ana-SiC crystal structure; both variants contain more than 200 distinct polytypes, although cubic b-SiC and Wurtzite are popular due to their close packing structure; both forms present within these crystal structures than they could ever form with all their 200 variations!
Silicon carbide’s low density, high mechanical strength, excellent oxidation resistance and thermal shock resistance, small high-temperature creep rate, thermal conductivity and elastic modulus of elasticity all combine to give this structural ceramic an impressive corrosion resistance that makes it irreplaceable in many industrial applications.
High Young’s Modulus
Silicon carbide ceramics possess an excellent Young’s modulus and exhibit almost linear elastic behavior up to failure, leading to excellent dimensional stability. This feature makes ceramic components ideal for applications in harsh environments due to their resistance against corrosion, abrasion and erosion while withstanding thermal shock shockwaves with ease and providing unparalleled resistance against oxidation.
Chemically vapor deposited C/C-SiC exhibits consistent strength and Young’s modulus up to temperatures of 1600 degC when processed under vacuum conditions, according to Maier16’s investigation of spark plasma sintered B4C samples without sintering additives and discovered that its strength and Young’s modulus decreased with increasing temperature, while remaining higher than typical commercial RS-SiC grades.
The graph bars on the material properties cards further down this page compare silicon carbide’s values with other non-oxide engineering ceramics, providing an approximate representation of its characteristics for use as design considerations. Please be aware that this comparison does not serve as an authoritative source.
Excellent Stability
Silicon carbide is an extremely stable material with superior heat endurance and chemical corrosion resistance. As such, it makes an ideal refractory ceramic material for manufacturing high-quality components requiring strength, thermal conductivity and low thermal expansion coefficient; with its excellent hardness and wear resistance characteristics. Furthermore, silicon carbide has many uses within mechanical parts manufacturing such as piston rings and mechanical seals; in high temperature applications like electric furnaces/burners as well as catalyst carrier nuggets/tower packing for fluidized bed reactors.
Silicon carbide stands out among fine ceramic materials by maintaining its strength and stiffness at temperatures up to 1400degC without plastic deformation or softening, making it one of the best corrosion resistance and hardness characteristics of sintered ceramics. As it offers unparalleled corrosion resistance and hardness properties, silicon carbide has become popular as an automotive brake and clutch material, bulletproof plates, nozzles, electronic equipment components that operate in high temperature/frequency environments and food industry applications. It is toxicologically safe as well.
Saint-Gobain Hexoloy(r) is a high-performance SiC ceramic that combines advanced properties to deliver exceptional performance under demanding end use conditions, making it an indispensable component for cutting-edge technologies and industrial applications.