Boron carbide is a kind of black crystal with a metallic luster, also known as black diamond, which belongs to inorganic nonmetallic material. At present, everyone is familiar with boron carbide material may be because of the application of bullet-proof armor, because it has the lowest density in ceramic materials, has the advantages of high elastic modulus and high hardness, and can achieve good use of micro fragmentation to absorb projectile energy effect while minimizing the load. But boron carbide has many other unique properties that could make it useful in abrasives, refractories, the nuclear industry, aerospace, and other fields.
In terms of physical properties, the hardness of boron carbide for sale is only after that of diamond and cubic boron nitride, and it can still maintain high strength at high temperatures, so it can be used as an ideal high-temperature wear-resistant material. Boron carbide has a very low density (theoretical density is only 2.52g /cm3), which is lighter than ordinary ceramic materials and can be used in aerospace fields. Boron carbide has a strong neutron absorption capacity, good thermal stability, and melting point of 2450 ℃, so it is also widely used in the nuclear industry. Meanwhile, its neutron absorption capacity can be further improved by adding ELEMENT B. Boron carbide materials with specific morphology and structure also have special photoelectric properties. In addition, boron carbide has the advantages of high melting point, high elastic modulus, low expansion coefficient, and good oxygen absorption capacity, which make it become a potential application material in many fields such as metallurgy, chemical industry, machinery, aerospace, and military industry. For example, wear-resistant parts, bulletproof armor, reactor control rods, and thermoelectric elements.
In terms of chemical properties, boron carbide does not react with acid, alkali, and most inorganic compounds at room temperature, and hardly reacts with oxygen and halogen gases at room temperature, so its chemical properties are stable. In addition, boron carbide powder, as a boriding agent of steel, is activated by halogen, which penetrates boron into the surface of the steel to form iron boride film, thus enhancing the strength and wear resistance of the material, and its chemical properties are excellent.
The application of boron carbide powder for sale as an abrasive is mainly used in the grinding and polishing of sapphire. Among the superhard materials, the hardness of boron carbide is superior to alumina and silicon carbide, second only to diamond and cubic boron nitride. Sapphire is the most ideal substrate material such as semiconductor GaN/Al 2O3 light-emitting diode (LED), large-scale integrated circuit SOI and SOS, and superconducting nanostructured films. The surface smoothness of sapphire is very high and must reach the degree of super-smooth without damage.
From the point of view of the material and abrasive field, the best materials for processing and grinding sapphire crystals are artificial diamond, boron carbide, silicon carbide, and silicon dioxide. The hardness of an artificial diamond is too high (Mohs hardness 10), which will scratch the surface of the sapphire crystal and affect the transmittance of the crystal, and the price is expensive. Silicon carbide cutting usually roughness RA is high, flatness is poor; And silica hardness is not enough (Mohs hardness 7), grinding force is poor in grinding engineering time, labor.
Boron carbide has the characteristics of oxidation resistance and high-temperature resistance and is generally used as advanced shaped and unshaped refractory material widely used in various fields of metallurgy, such as iron and steel stoves, kiln tools, and so on.
With the energy saving and consumption reduction of the iron and steel industry and the need for smelting low carbon steel and ultra-low carbon steel, the research and development of low carbon magnesium carbon brick with excellent performance (carbon content generally <8%) is increasingly concerned by the industry at home and abroad. Currently, usually by improving the carbon structure, optimizing the structure of magnesia carbon brick matrix, increasing effective antioxidants, and other measures to improve the use performance of low-carbon magnesia carbon brick, which adopts industrial-grade consisting of boron carbide and part of the graphitized carbon black composite powders, graphitized carbon black as carbon source and antioxidant used in low-carbon magnesia carbon brick, good results have been achieved.
Due to boron carbide at high temperature will occur certain softening, so can be attached to the surface of other material particles, even the product densification, the surface of the B2O3 oxide film can form certain protection, and play an antioxidant role. At the same time, because the reaction generated columnar crystals distributed in the matrix and gap of refractory materials, thus reducing porosity, improving the strength of medium temperature, and the volume expansion of the crystal, can heal volume shrinkage, and reduce cracks.