Hexagonal boron nitride (h-BN) powder, commonly referred to as “white graphite,” is an advanced functional material that has garnered significant attention in the field of materials science. Thanks to its unique physicochemical properties, it demonstrates immense application potential in numerous cutting-edge fields, including high-temperature insulation, lubrication, coatings, electronic heat dissipation, and environmental protection. This article will delve into the core characteristics, key applications, and future development trends of hexagonal boron nitride powder.
Hexagonal boron nitride powder is called “white graphite” because its crystal structure closely resembles that of graphite, consisting of a two-dimensional hexagonal honeycomb lattice formed by boron and nitrogen atoms. However, it is not merely a substitute for graphite but rather an “upgraded” material with superior performance.
Ultra-High Thermal Stability
h-BN can withstand temperatures of approximately 1000°C in air and can even endure temperatures as high as 2850°C in an inert environment.
Excellent Lubricating Properties
Thanks to its graphite-like layered structure, it has an extremely low interlayer friction coefficient (0.15–0.70) and maintains stable lubrication performance even at high temperatures, earning it the reputation as a “high-temperature lubricant.”
Excellent Chemical Inertness
It exhibits extremely low wettability toward most acids, alkalis, salts, as well as molten metals (such as aluminum, magnesium, and copper) and glass, effectively preventing corrosion and adhesion.
Outstanding Electrical Insulation and Thermal Conductivity
As a material with high electrical resistivity, its thermal conductivity reaches 1700–2000 W/m·K, making it an ideal material for insulation and heat dissipation.
The particle size and purity of hexagonal boron nitride (h-BN) powder are key factors determining its performance in various applications. Industrial-grade powder typically comes in a range of particle sizes, from the nanometer to the micrometer scale, to meet the requirements of different processes.
Key Application Areas
1. High-Temperature Industries and Casting
In metal casting and glass manufacturing, h-BN powder is used as a mold coating. It effectively prevents molten metal from adhering to the mold, reduces demolding resistance, and thereby improves casting precision and mold lifespan.
2. Electronics and Semiconductor Heat Dissipation
Due to its high thermal conductivity and excellent electrical insulation, h-BN powder is an ideal choice for manufacturing heat dissipation coatings for high-performance electronic components. It effectively prevents carbon contamination and enhances the thermal efficiency and reliability of devices.
3. Environmental Protection and Catalysis
Research indicates that h-BN films perform exceptionally well in wastewater treatment, effectively adsorbing dyes, oil contaminants, and metal ions, offering a new approach to addressing global water scarcity.
4. Coatings and Coating Materials
When added to coatings, h-BN powder imparts properties such as high-temperature resistance, anti-adhesion, wear resistance, and self-cleaning, making it widely used in military, aerospace, and high-temperature operating environments.
Currently, BN(CHINA) Technology’s h-BN products are synthesized using advanced continuous calcination equipment, with an annual production capacity of 1,000 tons. The products offer stable performance, strong bulk supply capabilities, and significant cost advantages. Four specifications are currently available: PBN700 (purity ≥99.5%), PBN500 (purity >99%), PBN300 (purity >98%), and PBN100 (purity >97%). The crystalline particle size of these four products ranges from 1 to 5μm, and powder particle sizes with a D50 between 4μm and 20μm are available. These four product specifications have been successfully applied in industries such as boron nitride ceramics, high-temperature coatings, release agents, lubricants, thermal conductive fillers, and high-temperature insulation materials.
