What is Silicone carbide?
Silicon carbide (SiC) is a silicon and carbon compound with the chemical formula SiC. The most basic method of making silicon carbide is to heat silica sand and carbon in an Acheson graphite electric resistance furnace to temperatures ranging from 1,600° C (2,910° F) to 2,500° C (4,530° F).
Silicon carbide (SiC) is also known as carborundum. It is found naturally as the mineral moissanite named after the French chemist Henry Moissan who discovered it. This mineral is considered to be very rare.
In its pure state, SiC is colourless; impurities can produce a variety of hues.
Why Silicone carbide is important?
Since 1893, artificial silicon carbide powder has been manufactured for use as an abrasive.
Sintering may fuse silicon carbide grains together to make highly hard ceramics, which are commonly utilized in applications requiring great durability.
SiC ceramics have outstanding thermal shock resistance owing to their low thermal expansion, high thermal conductivity, and strength at high temperatures (which remains up to 2,000° C [3,600° F], unlike that of most metals).
What are the uses of Silicon carbide?
- High-temperature load-bearing strength and dimensional stability are noteworthy in SiC ceramics.
- Industrial applications of silicon carbide as hard ceramic occur in the sectors of metallurgy, metal mining, chemicophysical, automotive engineering (e.g., body and brake disks), electrical engineering (e.g., semiconductors), electronics, and solar energy.
- SiC is used in car brakes as a replacement for asbestos following concerns over whether asbestos could enter the lungs of individuals working on brake assembly lines.
- Silicon carbide also can be used as armor for military land vehicles and body armour for infantrymen.
- SiC has also been investigated as a potential material to be used in nuclear fuel.
- This high-temperature performance can be used for gas turbine engine components, for example, and for rocket nozzles.
- SiC is also used extensively in refractories, kiln furniture, and other structural components that are subjected to high temperatures.
- A very thin coating of silicon carbide on a magnesium oxide crystal provides an optical window that is transparent to wavelengths from about 0.2 micrometre to about 7 micrometres; such windows are used in infrared spectroscopy instruments.
What is the Acheson Process?
Pure silica sand and finely split carbon (coke) are reacted in an electric furnace at temperatures ranging from 2,200°–2,480° C (4,000°–4,500° F) in the Acheson process.
The high temperature causes silicon and carbon to react within a few hours to form silicon carbide (SiC), which is relatively pure. This method is much less costly than the earlier method of reacting coke with sand at 1,800° C (3,300° F) in a sulfur-containing atmosphere.
The Acheson process produces both monocrystalline and polycrystalline SiC.
Silicon carbide fibres are produced as a final result. Continuous process fibres are made from a series of reactions in which polycarbosilane is converted to silicon carbide whiskers or continuous filaments. These filaments are then consolidated into shapes by hot pressing or reaction bonding.
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