Application field

Boron carbide (B4C), is a very hard artificial inorganic non-metallic material, its Mohs hardness of 9.36, microhardness of 5500~6700kg/mm2, second only to diamond and cubic boron nitride.

The crystalline structure of boron carbide is hexagonal crystal. The density is 2.52g/cm3, the melting point is 2450℃, the coefficient of linear expansion is 4.5×10-6/℃ (20~1000℃), the thermal conductivity is 121.42W/(m·K) (100℃), 62.80W/(m·K) (700℃). The resistivity is 0.44Ω·cm (20℃), 0.02Ω·cm (500℃). Boron carbide is insoluble in water and organic solvents, strong chemical stability, acid and alkali corrosion resistance, almost does not react with all acid and alkali solutions, and can resist the oxidation of air at 1000℃, with quite high chemical stability.

Boron carbide has a very high grinding capacity, is an excellent grinding material and wear resistance material, its grinding capacity is more than 50% of silicon carbide, than corundum grinding capacity 1 to 2 times higher. At the same time, it has a large thermal neutron capture cross section and a strong neutron absorption capacity, so it is called a neutron absorber.

The main uses of boron carbide include:

(1) Fine high-grade grinding materials

The grinding efficiency of boron carbide powder is extremely high, so it is often used as a grinding medium for grinding, grinding, drilling and polishing of hard materials such as sapphire, ceramics, tools, bearings, and cemented carbide. Especially in sapphire crystal processing, boron carbide is the most ideal grinding material.

(2) Industrial special ceramic materials

Abrasive parts and structural parts such as sand blasters, sealing rings, nozzles, bearings, plungers of mud pumps, pestles and rocket launchers made of boron carbide powder are widely used in machinery, aerospace, national defense, electronics, and automotive industries for their high hardness, high temperature resistance and superior elastic modulus.

(3) Shielding and control materials for the nuclear industry

Boron carbide material has a large thermal neutron capture cross section, so it has excellent neutron absorption and radiation resistance, and is internationally recognized as the best control material and shielding material for nuclear reactors. Boron carbide has been successfully applied in the selection of control materials and shielding materials for fast neutron breeder reactor and high temperature gas cooled reactor.

(4) boron carbide bulletproof armor

Boron carbide material has high hardness, high strength, high toughness and low density of "three high and one low" characteristics, especially suitable for use in lightweight bulletproof armor, such as helicopter gunships, tanks, armored personnel carriers, ships and individual human protection. It can not only minimize the weight of the combat unit, play the tactical mobility, but also the bulletproof performance is stable, which can significantly improve the battlefield survival rate under harsh conditions.

(5) boron carbide wear resistant alloy powder

Boron carbide powder is combined with metal to form metal based alloy powder. After the special surface treatment of this material, the original mechanical parts are more resistant to wear and acid and alkali corrosion, which can improve the life of mechanical parts.

(6) High grade refractory material

Boron carbide has the characteristics of high temperature resistance and oxidation resistance, and can be used as an antioxidant additive for high-grade refractory materials, which can densify the product, prevent the oxidation of carbon in carbon-containing refractory materials, and reduce the porosity. It is often used in the steel industry as a key part of high temperature resistance and erosion resistance.

(7) Chemical industry additives

Boron carbide chemical performance is stable, and acid, alkali solution does not react, has a high chemical potential, so it is widely used in the production of other boron-containing materials, such as zirconium boride, titanium boride, boron halide, boron nitride, metal boride, elemental boron, hydrogen boride and so on.

(8) Rocket solid fuel additives

In addition to hydrogen and boron, boron carbide is also a high-energy compound that can be applied to high temperature hot spot conversion, in a powder state as a solid fuel additive for transport rockets.