Black silicon carbide (SiC), also known as diamond grit or refractory sand, is a black crystal that is brittle yet sharp. It also possesses moderate thermal and electrical conductivity, making it second only to diamond, cubic boron nitride, and boron carbide as an abrasive. The preparation process for black silicon carbide is the same as for green silicon carbide, using quartz sand, petroleum coke, and high-quality silica as the primary raw materials, and is smelted under high pressure in a resistance furnace.
Application areas of black silicon carbide:
Due to its stable chemical properties, high thermal conductivity, small thermal expansion coefficient and good wear resistance, black silicon carbide can be used as:
1. Used as abrasives and grinding tools, it can be used for grinding and polishing optical glass, cemented carbide, titanium alloy, and bearing steel, and for sharpening high-speed steel tools. Black silicon carbide is primarily used for cutting and grinding materials with low tensile strength, including cutting and precision grinding of crystals, precision grinding of hard glass, slicing of single-crystal silicon and polycrystalline silicon rods, precision grinding of single-crystal silicon wafers, machining of superhard metals, and machining of soft metals such as copper and copper alloys. It can also be used as bonded and coated abrasives.
2. Made into high-grade refractory materials, it is resistant to thermal shock, small in size, light in weight and high in strength. It is mainly used for high-temperature furnace components and supports, with good energy-saving effects.
3. Used as functional ceramics, it can not only reduce the capacity of kiln tools, but also improve the quality of kiln products and shorten the cycle. It is an ideal indirect material for ceramic glaze baking and sintering.
4. In the nonferrous metal industry, in addition to being used as resistant linings for various smelting furnaces, it is also used as a steelmaking deoxidizer, cast iron structure improver, etc.
5. In the electrical industry, black silicon carbide materials are also widely used as electric heating elements, high-temperature semi-superconductor materials, far-infrared panels, lightning arrester valve plate materials, etc.
