Silicon Carbide News - ceramic atijolart

Silicon carbide is one of the hardest known substances, used as a synthetic abrasive and found naturally as moissanite in meteorites; it can also be mined.

SiC’s wide bandgap properties allow it to minimize switching losses while supporting higher frequencies, making it ideal for use in high voltage power semiconductor devices like inverters in electric vehicles (EV).

What is Silicon Carbide?

Silicon carbide, or SiC, is an extremely hard chemical compound composed of silicon and carbon that naturally occurs as the rare gem moissanite; however, for over 100 years silicon carbide powder and crystal have been mass produced for use as an abrasive and to create ceramic components used in car brakes and clutches or even bulletproof vests. With its dense crystalline structure made up of nanocrystals silicon carbide is both extremely hard, highly durable, and heat-resistant properties.

Modern producers of silicon carbide for use in abrasives and metallurgical industries use the Acheson process, in which pure silica sand mixed with finely ground coke is placed into a brick electrical resistance-type furnace and electrified; electricity passes through this resistance furnace. Carbon from coke and silicon from sand react chemically, producing SiC at the core and carbon monoxide gas at its surface. This process typically occurs at very high temperatures ranging between 1700-2500 degC. This process produces a solid cylindrical ingot with layers varying from graphite on the inside, through graphene-rich high-grade SiC and coarse crystalline structure to lower grades like b-SiC for use in metalworking processes as well as unreacted material on its exterior that can be remelted if required. SiC can come out either black or green depending on which raw materials were used during processing.

IPS Ceramics provides all major types of silicon carbide as well as an extensive selection of kiln furniture products to work with this remarkable material. Our team of expert ceramics professionals can assist in choosing which SiC type will best meet your application, while providing tools and machinery necessary for proper grinding media usage for producing desired end products.

SiC is generally considered inert with no toxicological properties and low acute toxicity when handled and prepared according to standard practices, although prolonged exposure may cause mild skin irritation as well as altering inhalation tuberculosis in experimental animals, potentially leading to extensive fibrosis and disease progression. For more information please see the Human Toxicity Data Sheet of this compound.

How is Silicon Carbide Made?

Silicon carbide, more commonly referred to by its chemical symbol SiC, has numerous applications as an abrasive, ceramic and semiconductor material. As one of the hardest materials available and being strong and durable – second only to diamond in terms of tensile strength – silicon carbide boasts superior heat and chemical inertness even at elevated temperatures making it an indispensable material in industrial refractories.

Edward Acheson first artificially synthesized silicon carbide in 1891 when he discovered tiny black crystals of it in an electrically heated melt of carbon and alumina, and named the process after himself; today it remains the primary method for manufacturing silicon carbide used in abrasives, metallurgy, refractories as well as producing natural moissanite minerals.

Nowadays, silicon carbide is manufactured through innovative processes for use in various specialty applications. Reaction-bonded SiC (CB) is produced by mixing powdered silicon and carbon with plasticizer and shaping it into an object; then burning off any excess plasticizer; finally reacting further with gaseous or liquid silicon to form additional SiC particles. Reaction-bonded SiC provides cost-effective wear-resistant coatings as well as high-quality crucibles used to melt and hold metals.

Chemical vapour deposition and single-crystal growth methods of producing silicon carbide produce other variants. This involves growing silicon and carbon in a vacuum or at high temperature into a boule, similar to how wafers are made for solid-state electronic devices. Once complete, this boule can then be doped with nitrogen or phosphorus for producing an n-type semiconductor or beryllium, boron or aluminum for producing p-type semiconductors.

Silicon carbide can be divided into multiple categories depending on its grain size, binder composition, purity level and density, particle shape or how it’s sintered. Abrasive grades of silicon carbide may be mixed with other compounds and ground into granules for industrial refractories; such granules are then used in cements, bricks and crucibles as cement replacement. Refractories differ based on how precisely their formulation was mixed and their ability to resist high temperature and chemical stress resistance – each application demands its own quality assessment of quality!

What are the Main Applications of Silicon Carbide?

Silicon carbide has many applications; it is an inert material with excellent thermal conductivity, an electrical insulator and has rainbow-like luster due to the passivation layer of silicon dioxide forming on its surface. Furthermore, it has excellent resistance against many organic and inorganic acids, alkalis and salts except hydrofluoric acid which could potentially cause corrosion issues.

SiC is an attractive semiconductor material for use in power electronics due to its wide band gap and advantages over silicon semiconductors, such as higher voltage tolerance, faster operation speed and reduced junction losses. A single crystal of SiC can be deposited as tetrahedral formation with primary coordination tetrahedra consisting of four carbon and four silicon atoms linked at their corners and stacked into polar structures; dopants may then be added for either n-type or p-type semiconductor production (Mantooth Zetterling Rusu).

Pure silicon carbide can be created through the Lely process, in which powdered SiC is sublimed into high-temperature species such as silicon, carbon, silicon dicarbide and disilicon carbide at 2500 degC in an argon gas atmosphere. Cubic silicon carbide crystals may then be grown using chemical vapor deposition with silane, hydrogen and nitrogen as precursors to produce single crystals sized up to 2 cm in size through CVD growth processes such as chemical vapor deposition.

Silicon carbide’s resistance to abrasion is another key quality. This property makes it popularly used as an abrasive material in machining and grinding processes, as well as lapidary applications involving fiber optic strand polishing prior to splicing. Furthermore, silicon carbide jewelry often makes use of it.

Due to being one of the two hardest materials on Earth, silicon carbide parts can be extremely challenging to machine with precision dimensions required by sintered silicon carbide products. Sintered silicon carbide must pass a series of rigorous tests and inspections in order to meet certain mechanical properties requirements; inhalation exposure may even lead to lung damage in humans including fibrosis.

What is the Future of Silicon Carbide?

Silicon carbide is one of the world’s hardest substances and must be cut with diamond-tipped blades in order to be cut. Yet despite this difficulty, silicon carbide stands to disrupt multibillion-dollar industries; for example, electric vehicle inverters and chargers incorporating silicon carbide operate at higher temperatures than their silicon counterparts while their switches can be half the size, leading to weight reduction, cost reduction, complexity reduction and longer battery ranges compared with standard silicon devices.

As more people switch to electric vehicles (EVs), demand for silicon carbide power electronics will grow exponentially. This rapid expansion is driven by large area, low cost wafers produced at specialized facilities using sophisticated equipment that enables crystal growth within vacuum environments; then these wafers can be used in manufacturing power semiconductors and other devices.

Power semiconductors make up the bulk of global silicon carbide market and are utilized in an array of applications, from electric vehicles and wind turbines to smartphones and computers. Furthermore, this technology has recently seen widespread adoption within oil and gas industries as a means of improving safety and efficiency.

Manufacturers are investing in production capacity to meet growing demand for silicon carbide devices, like those offered by SK Siltron of Bay City, Michigan, to meet this need for quality SiC wafers financed through a loan from the Department of Energy (DOE).

Other producers are responding to rising demand by entering emerging markets. China’s silicon carbide and gallium nitride semiconductor industry is experiencing rapid expansion thanks to an upsurge in power semiconductor demand from electric vehicles (EVs) and industrial applications.

Silicon carbide has long been recognized for its refractory and abrasive properties as well as its ability to operate under harsh conditions, making it ideal for robotics, manufacturing facilities, motor drives and cutting tools and grinding wheels requiring strength and wear resistance. Industrial applications now represent one of the largest markets for silicon carbide.