Hexagonal Boron Nitride Ceramics — Becoming the New Favorite in Various Industries

1. Aerospace Field

h-BN exhibits high thermal stability and low dielectric loss, making it one of the suitable materials for manufacturing high-temperature antenna covers/windows. Although it has issues such as low hardness and poor rain erosion resistance, the incorporation of Silicon Nitride, silicon oxide, and other materials into h-BN ceramics facilitates the improvement of sintering characteristics while also harnessing the advantages of each component. This composite approach can meet the complex performance requirements for heat protection, load-bearing, and wave transmission of antenna cover/window components under high Mach number flight conditions.

For Hall thrusters applicable to satellite and deep space probe attitude control, orbit insertion, transfer, and maintenance flight missions, the key components of the nozzle material are required to possess good heat resistance, anti-cyclic thermal shock, high-temperature electrical insulation, resistance to ion sputtering erosion, and suitable secondary electron emission coefficients. h-BN ceramic is the most suitable material for the fabrication of nozzle components. Russia, Japan, the United States, and the European Union have all conducted extensive research on h-BN series ceramic nozzle materials for Hall thrusters and have successfully applied them in related spacecraft. Our country has also completed in-orbit experimental verification of Hall thrusters and their nozzle components on related satellite models and other spacecraft.

2. Metallurgy Industry

h-BN and its complex phase ceramics have been widely used as high-temperature refractory materials, such as TiB,-AIN-BN complex phase ceramic evaporation boat, SigN-BN separation ring, special metal high-temperature electrolyzer, high-temperature collapse, casting shell, etc. With the depth of research and the expansion of application needs, the performance of this series of ceramic materials has been greatly improved, and the application fields have been expanded day by day. 

Thin strip continuous casting technology is a new type of thin strip steel production process, compared with the traditional hot rolling process, it has the advantages of less equipment investment, simple production process, small energy consumption, and low product cost. The side sealing plate is an important leak-proof device added at both ends of the casting roller to form a liquid metal melt pool between the casting file, which can play a role in restraining metal liquid, promoting the forming of thin strips, ensuring the quality of the edge of the thin strip, etc., which requires the material to have good thermal shock resistance, molten steel erosion resistance, high temperature volume stability, non-wetting with molten steel and other characteristics and appropriate Wear Resistance. After experiencing various materials such as traditional refractories and fused quartz oxidation errors, h-BN has been recognized as the most promising material. Japan, the United States, Russia, Germany and other metallurgical technology powers have systematically studied h-BN complex ceramic side sealing plates, forming SiAlON-BN, SiN-BN, AIN-BN ZrO2-BN and other series of materials, and relevant research institutions in our country have also completed experimental tests under simulated working conditions. 

3. Electronics Industry

h-BN has high insulation and thermal conductivity, and can be used as a thermal management device in electronic circuits. When single-layer or few-layer h-BN nanomaterials prepared by chemical vapor deposition or liquid phase stripping are applied to the surface of the chip, they can not only play a protective role, but also use the excellent lateral heat transfer ability brought by their special two-dimensional structure to quickly propagate the local hot spot heat of high-power electronic devices along the lateral direction, reducing the local maximum temperature, thereby improving the life and reliability of the device. In addition, h-BN powder is also an ideal polymer filler, which can be added to resin, rubber, plastics and other materials to improve thermal conductivity and improve insulation properties, which plays an important role in the application of polymer materials in flexible electronic devices.

In recent years, with the increasing heat of graphene research year by year, two-dimensional boron nitride nanosheets have also received widespread attention, because the structure of the two is similar but the electrical properties are very different, they can be arranged layer by layer to form high-quality planar heterojunctions, which have the characteristics of small lattice mismatch, high carrier mobility, adjustable bandwidth and other characteristics, and have broad application prospects in micro-nano structures of high-frequency transistors and optoelectronic devices.

4. Other Uses in the Industry

h-BN also has a wide range of applications in other fields: boron-containing compounds have certain anti-neutron radiation properties, h-BN can also be used in packaging materials to prevent neutron irradiation, structural parts of atomic reactors, etc.: b-BN has high temperature resistance, chemical stability and good high-temperature lubrication properties, so that it can be used in high-temperature lubricants or mold release agents, melt anti-stick agents, etc.; High-purity h-BN has good adhesion, soft and lubricated texture, and has a lower friction coefficient than traditional cosmetic powders (such as talc, mica, etc.), and can be used as a filler for high-end cosmetics such as powder, lipstick, lip gloss, skin care products, etc.: recent studies have shown that various forms of h-BN can trigger or catalyze a series of reactions through the formation of some free radicals, including acetylene chlorination reaction and propane dehydrogenation reaction, so it can be used as a carrier for catalysts, and can also be used as a carrier for catalysts, It is directly applied to catalytic reactions by modification and other means, showing good application potential.