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CARBOREX Silicon Carbide

Washington Mills AS manufactures high quality silicon carbide crude, macro grits, micro grit powders, and sub-micron powders. Washington Mills AS controls the quality of its silicon carbide from start to finish. The raw materials used in the furnace all the way to the shape, size and chemistry of the final micro grits are all carefully engineered and controlled to produce a superior product. Washington Mills AS manufactures its silicon carbide according to different specifications depending on the customers' needs. The information below represents typical technical data, but please contact us to find out more about our specific products to suit your particular application.

Our silicon carbide is a man-made material manufactured through heating silica sand and carbon to high temperatures in the Acheson furnace technique. Silicon carbide is an extremely hard material (Mohs hardness 9.25), is chemically inert and does not melt. Silicon Carbide has a high thermal conductivity, a low coefficient of thermal expansion, is thermal shock and abrasion resistant, and has strength at high temperatures. Silicon carbide’s varied properties makes it an effective material in many different applications.

Data sheet - General Data

CHEMICAL PROPERTIES

Silicon carbide will not dissolve in acids or in bases, but is easily attacked by alkaline melts and by most metal and metal oxide melts. For practical applications the temperature limits are 1.500 °C in an inert gas or reducing atmosphere. The impurities in technical silicon carbide primarily consist of free C and SiO2 in varying amounts depending on the type of product. In addition, some Si and Fe and small quantities of Al and Ca occur. Mol weight: 40.096. Pure SiC is composed of 29.95 % C and 70.05 % Si.

PHYSICAL PROPERTIES

Chemically pure silicon carbide is colourless. Traces of nitrogen in the atomic grid give a green colour, while presence of aluminium changes the colour towards grey to blue/black. Extreme hardness, high thermal conductivity and low linear thermal expansion are some of the properties that make silicon carbide an outstanding material in its main areas of usage. The following physical data can be considered as guidelines:

HARDNESS

Mohs scale Between 9 and 10
Knoop scale 25.000–30.000 N/mm2

THERMAL CONDUCTIVITY

20 °C 0.41 W/cm °C
1000 °C 0.21 W/cm °C

LINEAR THERMAL EXPANSION

20–1000 °C 5.1 . 10-6/ °C
20–2000 °C 5.8 . 10-6/ °C

SPECIFIC HEAT

25 °C 0.67 J/g °C
1000 °C 1.26 J/g °C
Specific density 3.21 g/cm3
Bulk density 0.5–1.7 g/cm3

MELTING POINT

Silicon Carbide does not melt, but dissociation starts at about 2.300 °C