Silicon carbide SiCSilicon carbide (SiC) corresponds to the mineral moissanite, and has a
hardness of about 9.5 (Mohs scale) or 2,500 (Knoop), and specific
gravity 3.2. It is insoluble in acid and is infusible but decomposes above
2,230°C (4,060°F). It is manufactured by fusing together coke and sand
in an electric furnace of the resistance type. Sawdust is used also in the
batch and burns away, leaving passages for the carbon monoxide to
escape. The grains are characterized by great brittleness. Abrasives of
silicon carbide are best adapted to the grinding of low-tensile-strength
materials such as cast iron, brass, bronze, marble, concrete, stone, and
glass. It is available under several trade names such as Carborundum,
Carbolon, Crystolon.
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