Boron Nitride hmoov

specification

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Chinese name: hexagonal boron nitride, boron nitride

English name: Boron Nitride

Molecular formula: BN

Molecular weight: 24.18 (according to 1979 international atomic weight)

Quality standard: 98%, 99%

Enterprise standard: Q/YLH001-2006

PIB: 2850001200

Tus lej CAS: 10043-11-5

Low temperature boron nitride is synthesized by mixing borax and ammonium chloride in a reaction furnace at a reaction temperature of 1000-1200°C. High-temperature boron nitride is synthesized by mixing boric acid and melamine through a high-temperature calcination reaction at 1700.

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Boron nitride is a crystal composed of nitrogen atoms and boron atoms. The crystal structure is divided into: hexagonal boron nitride (HBN), close-packed hexagonal boron nitride (WBN) and cubic boron nitride, among which hexagonal boron nitride crystals The structure has a similar graphite layered structure, showing a white powder that is loose, lubricated, easy to absorb moisture, and light in weight, so it is also called "white graphite".

The theoretical density is 2.27g/cm3, the specific gravity is 2.43, and the Mohs hardness is 2.

Hexagonal boron nitride has good electrical insulation, thermal conductivity, chemical stability, no obvious melting point, heat resistance to 3000 ℃ in 0.1MPA nitrogen, heat resistance to 2000 ℃ in a neutral reducing atmosphere, in nitrogen and The operating temperature in argon can reach 2800 ℃, and the stability in oxygen atmosphere is poor, and the operating temperature is below 1000 ℃.

The expansion coefficient of hexagonal boron nitride is equivalent to that of quartz, but the thermal conductivity is ten times that of quartz. It also has good lubricity at high temperature. It is an excellent high-temperature solid lubricant with strong neutron absorption capacity, stable chemical properties, and chemical inertness to almost all molten metals.

Hexagonal boron nitride is insoluble in cold water. When the water is boiled, it hydrolyzes very slowly and produces a small amount of boric acid and ammonia. It does not react with weak acids and strong bases at room temperature. It is slightly soluble in hot acids. Use molten sodium hydroxide, potassium hydroxide processing to decompose. It has considerable anti-corrosion ability to various inorganic acids, alkalis, salt solutions and organic solvents.

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Boron Nitride Parameters

1. High heat resistance: sublimation at 3000℃, its strength is 2 times that of room temperature at 1800℃, and it will not break when cooled to room temperature for dozens of times at 1500℃, and will not soften at 2800℃ in inert gas.

2. High thermal conductivity: The hot-pressed product is 33W/M.K. Like pure iron, it is a thermally conductive material in ceramic materials above 530 °C.

3. Low thermal expansion coefficient: The expansion coefficient of 2×10-6 is second only to quartz glass, which is the smallest among ceramics. In addition, it has high thermal conductivity, so it has good thermal shock resistance.

4. Excellent electrical properties: good high-temperature insulation, 1014Ω-cm at 25°C, and 103Ω-cm at 2000°C. It is a better high-temperature insulating material in ceramics, with a breakdown voltage of 3KV/MV and low dielectric loss of 108HZ. When it is 2.5×10-4, the dielectric constant is 4, and it can transmit microwave and infrared rays.

5. Good corrosion resistance: with general metals (iron, copper, aluminum, lead, etc.), rare earth metals, precious metals, semiconductor materials (germanium, silicon, potassium arsenide), glass, molten salts (crystal stone, fluoride , slag), inorganic acids, alkalis do not react.

6. Low coefficient of friction: U is 0.16, which does not increase at high temperature. It is more resistant to high temperature than molybdenum disulfide and graphite. The oxidizing atmosphere can be used up to 900 °C, and the vacuum can be used up to 2000 °C.

7. High purity: its impurity content is less than 10PPM, and its B content is greater than 43.6%.

8. Machinability: Its hardness is Mohs 2, so it can be processed into parts with high precision by general machining methods.

Scope ntawm daim ntawv thov

1. Boron nitride is a material with non-toxic, high temperature resistance, corrosion resistance, high thermal conductivity, high insulation and excellent lubricating properties.

2. It is both an electrical insulator and a thermal conductor, special electrolysis and resistance materials under high temperature conditions, insulators for high-voltage high-frequency electricity and plasma arcs.

3. It can be used as a solid-phase doping material for semiconductors, and a grease that resists oxidation or water.

4. High-temperature lubricant and mold release agent for models, boron nitride powder can also be used as a release agent for glass beads, and a mold release agent for glass and metal molding.

5. The superhard material processed by boron nitride can be made into high-speed cutting tools and drill bits for geological exploration and oil drilling.

6. Structural materials of atomic reactors, nozzles of aircraft and rocket engines, packaging materials to prevent neutron radiation, and heat shielding materials in aerospace.

7. It is non-toxic and harmless and has lubricity, which can be used as filler for cosmetics.

8. With the participation of catalyst, it can be converted into cubic boron nitride as hard as diamond after high temperature and high pressure treatment.

9. Make various evaporation boats for capacitor film aluminum plating, picture tube aluminum plating, display aluminum plating, etc.

10. Heat-sealing desiccant for transistors and additives for polymers such as plastic resins.

11. Various laser anti-counterfeiting aluminum plating, trademark bronzing materials, various cigarette labels, beer labels, packaging boxes, cigarette packaging boxes, etc.