Silicon Carbide (SiC) Ceramic for Sale | Advanced Ceramic Materials

Silicon Carbide Ceramics Structure

There are 250 crystalline forms of silicon carbide. The polymorphic feature of SiC is a large class of similar crystal structures called polymorphs. They are variants of the same compound, the same in two dimensions but different in three dimensions. Therefore, they can be viewed as layers stacked in a specific order.

Silicon Carbide Structure

Alpha silicon carbide (α-SiC) is the most common polymorph. It is formed at temperatures above 1700°C and has a hexagonal crystal structure (similar to wurtzite). The beta modification (β-SiC), with a zinc blende crystal structure, is formed at temperatures below 1700 °C.

Silicon Carbide Ceramics Specification

Compound Formula	SiC
Molecular Weight	40.1
Appearance	Black
Melting Point	2,730° C (4,946° F) (decomposes)
Density	3.0 to 3.2 g/cm3
Electrical Resistivity	1 to 4 10x Ω-m
Poisson's Ratio	0.15 to 0.21
Specific Heat	670 to 1180 J/kg-K

Silicon Carbide Ceramics Types

Material		Recrystallization Silicon Carbide	Silicon Nitride bonded Silicon Carbide
Properties	Units	RSiC	NSiC
Color	-	Black	Gray
Permeability	-	-	-
Density	g/cm3	2.7	2.8
Straightness	-	1‰	1‰
Hardness	Mohs Scale	9.5	9
Water Absorption	-	0	0
Flexural Strength（Typical 20℃）	Mpa	90	180
Compressive Strength （Typical 20℃）	Mpa	600	650
Coefficient of Thermal Expansion (25℃ to 800℃）	0-6/℃	4.7	5
Long-term Operating Temperature	℃	1650	1450
Thermal Conductivity (25℃）	W/m·K	23	15

Silicon Carbide Ceramics Applications

Until the invention of boron carbide in 1929, silicon carbide was the hardest synthetic material known. It has a Mohs hardness rating of 9, approaching that of a diamond. In addition, SiC crystal has fracture characteristics that make them extremely useful in grinding wheels and in abrasive paper and cloth products.

Its high thermal conductivity, together with its high-temperature strength, low thermal expansion, and resistance to chemical reaction and thermal shock, makes silicon carbide valuable in the manufacture of high-temperature bricks and other refractories.

SiC ceramic is also classed as a semiconductor, having an electrical conductivity between that of metals and insulating materials. This property, in combination with its thermal properties, makes SiC a promising substitute for traditional semiconductors such as silicon in high-temperature applications.

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Your Silicon Carbide Ceramics Supplier

Advanced Ceramic Materials (ACM) is a leading supplier of silicon carbide ceramic products of the highest quality for a wide range of applications. We are happy to provide advice on materials, design, and application. Feel free to contact us for any questions about SiC or other ceramic materials that are not listed on the website.

FAQ

Q: What Is Silicon Carbide Ceramic?

A: Silicon carbide ceramic (SiC) is an advanced ceramic material containing silicon and carbon. It occurs in nature as the extremely rare mineral moissanite. Synthetic SiC powder has been mass-produced since 1893 for use as an abrasive. Grains of silicon carbide can be bonded together by sintering to form very hard ceramics.

Q: Where Is Silicon Carbide Used?

(1) As an abrasive, it can be used as a grinding tool, such as a grinding wheel, oil stone, grinding head, sand tile, etc. (2) As a metallurgical deoxidizer and high-temperature resistant material. (3) A high-purity single crystal that can be used for manufacturing semiconductors and manufacturing silicon carbide fibers. Further Reading: Applications of Silicon Carbide Ceramics in These 4 Industries

Q: Is Silicon Carbide a Good Abrasive?

A: Silicon carbide has been used as an abrasive material since its discovery in 1891. The material is lightweight, has excellent thermal conductivity, and has low thermal expansion. It has very high abrasion resistance and is relatively cheaper when we talk about production. For these reasons, silicon carbide material is often applied as a loose or solid abrasive material in several applications. Silicon carbide abrasives are available in several forms (such as powder, sandpaper, grinding wheel, and etc.) depending on the applications they’re meant for.

Q: Why Is Silicon Carbide Used in Semiconductors?

A: Silicon carbide is not only the lightest, but also the hardest ceramic material and has excellent thermal conductivity, low thermal expansion and is very resistant to acids and lyes. Silicon Carbide (SiC) devices belong to the so-called wide band gap semiconductor group. They offer a number of attractive characteristics for high voltage power semiconductors when compared to commonly used silicon (Si). Silicon carbide behaves almost like a diamond. It is toxicologically safe and can be used in the food industry. In particular, the much higher breakdown field strength and thermal conductivity of SiC allow creating devices which outperform by far the corresponding Si ones.

Q: What Are the Different Commercial Forms of Silicon Carbide?

A: In commercial engineering applications, silicon carbide is produced in different forms. Sintered silicon carbide (SSC) Nitride bonded silicon carbide (NBSC) Reaction bonded silicon carbide (RBSC) Clay-bonded silicon carbide SiAlON bonded silicon carbide, also known as silicon nitride bonded silicon carbide (NBSC). Chemical-vapor-deposited silicon carbide (CVD) Silicon Carbide. CVD is an extremely pure form of silicon carbide compound.