Black silicon carbide is made of quartz sand, petroleum coke and high-quality silica as the main raw materials, and is smelted at high temperature in a resistance furnace. Its hardness is between corundum and diamond, its mechanical strength is higher than corundum, and it is brittle and sharp.
Among them: green silicon carbide is made of petroleum coke and high-quality silica as the main raw materials, and salt is added as an additive, and is smelted at high temperature in a resistance furnace. Its hardness is between corundum and diamond, and its mechanical strength is higher than corundum. There are two different crystals of commonly used silicon carbide abrasives. One is green silicon carbide, which contains more than 97% SiC and is mainly used to grind hard gold-containing tools.
The other is black silicon carbide, which has a metallic luster and contains more than 95% SiC. It is stronger than green silicon carbide, but has a lower hardness. It is mainly used to grind cast iron and non-metallic materials.
Uses of black silicon carbide:
1. Abrasives: Black silicon carbide is mostly used for grinding and polishing optical glass, hard alloy, titanium alloy and bearing steel, sharpening of high-speed steel tools, etc.; black silicon carbide is mostly used for cutting and grinding materials with low tensile strength.
2. Refractory materials: Black silicon carbide has good thermal shock resistance, so it is a high-quality refractory material. According to the production process of the product, it can be divided into recrystallized silicon carbide, products, high-temperature hot-pressed products, products with silicon nitride or clay as binders, etc. The main products and uses are: high-temperature furnace components, support parts.
3. Metallurgical and electrical industry: In addition to being used for various smelting furnace linings, it is also used as a steelmaking deoxidizer, cast iron structure improver, etc. The chemical element requirements of the black silicon carbide of the release agent are: Compared with the traditional steelmaking process of using coke and silicon powder to evacuate and deoxidize, the use of SiC release agent has the advantages of good steel quality and good working environment.
4. Other fields: 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 materials, etc.
