Silicon carbide Properties and Uses

- Sep 22, 2022 -

Silicon carbide Properties and Uses

Before the invention of boron carbide in 1929, silicon carbide was the hardest synthetic material known. It has a Morse hardness of 9, close to diamonds.

In addition to hardness, silicon carbide crystals also have fracture properties, which makes them useful in grinding wheels as well as in sandpaper and cloth products.

Its high thermal conductivity, coupled with its high-temperature strength, low thermal expansion and chemical resistance, make silicon carbide valuable in the manufacture of high-temperature bricks and other refractories.

It is also classified as a semiconductor with electrical conductivity between metal and insulating materials. The combination of this property and its thermal properties makes SiC a promising substitute for traditional semiconductors such as silicon in high temperature applications.

 

The discovery of silicon carbide

Silicon carbide was developed by American inventor Edward G. Acheson was in 1891. In trying to make rhinestones, Acheson heated a mixture of clay and coke powder in an iron bowl, using iron bowls and ordinary carbon arc lamps as electrodes. He found bright green crystals attached to carbon electrodes and thought he had prepared some new compounds of carbon and alumina from clay. He calls the new compound silicon carbide because the natural mineral form of alumina is called corundum. Finding the crystal close to the hardness of a diamond and immediately realizing the importance of his discovery, Acheson applied for a US patent. His early products were originally used to polish gems and cost as much as natural diamond powder. This new compound can be obtained from cheap raw materials and has a high yield, so it will soon become an important industrial abrasive.

Around the time Acheson discovered Henry, French Moissan produced a similar compound from a mixture of quartz and carbon. But in a 1903 publication, Mosang attributed the initial discovery to Acheson. Some natural silicon carbide has been found in the Canyon Dark meteorite in Arizona. Its mineralogical name is Mozamite.

 

Modern manufacturing

The modern silicon carbide manufacturing methods used in the abrasive, metallurgical and refractory industries are basically the same as those developed by Acheson. The mixture of pure silica sand and carbon is formed around the carbon conductor in the brick resistance furnace in the form of fine crushed coke. The electric current passes through the conductor and causes a chemical reaction. The carbon in the coke combines with the silicon in the sand to form silicon carbide and carbon monoxide gas. A furnace operation may last several days, during which the core temperature ranges from 2200 °to 2700 °C (4000 °to 4900 °F) to approximately 1400 °C (2500 °F) at the outer edge. Energy consumption exceeds 100000 kilowatt-hours per operation. At the end of the operation, the product consists of loosely woven green to black SiC crystal cores surrounded by some or all of the unconverted raw materials. Bulk aggregates are crushed, ground and screened into various sizes suitable for end-use.

 

For special applications, silicon carbide is produced through a variety of advanced processes. Reaction-bonded silicon carbide mixes silicon carbide powder with carbon powder and plasticizer, forms the mixture into the desired shape, burns the plasticizer, and then injects gaseous or molten silicon into the fired object, which reacts with carbon to form additional silicon carbide. The wear-resistant layer of silicon carbide can be formed by chemical vapor deposition, which is a process in which volatile compounds containing carbon and silicon react at high temperature in the presence of hydrogen. For advanced electronic applications, large SiC single crystals can be grown from steam; the ingots can then be cut into wafers that resemble silicon, which can be used to make solid-state devices. For reinforced metals or other ceramics, SiC fibers can be formed in a variety of ways, including chemical vapor deposition and firing of silicon-containing polymer fibers.

 

Silicon carbide Price

The price is influenced by many factors including the supply and demand in the market, industry trends, economic activity, market sentiment, and unexpected events.

If you are looking for the latest SiC price, you can send us your inquiry for a quote. (sales1@rboschco.com)

 

Silicon carbide Supplier

RBOSCHCO is a trusted global chemical material supplier&manufacturer with over 12-year-experience in providing super high-quality chemicals and nanomaterials. The company export to many countries including the USA, Canada, Europe, UAE, South Africa, Tanzania, Kenya, Egypt, Nigeria, Cameroon, Uganda, Turkey, Mexico, Azerbaijan, Belgium, Cyprus, Czech Republic, Brazil, Chile, Dubai, Japan, Korea, Vietnam, Thailand, Malaysia, Indonesia, Australia, Germany, France, Italy, Portugal, etc.

As a leading nanotechnology development manufacturer, RBOSCHCO dominates the market. Our professional work team provides perfect solutions to help improve the efficiency of various industries, create value, and easily cope with various challenges.

 

If you are looking for SiC powder, please send an email. (sales1@rboschco.com)