What are boron nitride (BN) ceramics?

Boron Nitride (BN) is an excellent advanced ceramic material with unique properties that set it apart in many demanding applications. It has a similar hexagonal crystal structure to graphite, hence the name hexagonal boron nitride (hBN). This unique boron nitride structure gives it a range of excellent properties that make it ideal for high temperature, high pressure, insulation and lubrication applications.

Our boron nitride ceramics are carefully crafted using a precision process to provide a superior combination of properties. From boron nitride powders to final boron nitride products, we are committed to providing high quality solutions that meet our customers' specific needs. The most common and widely used form of boron nitride is boron nitride with the chemical formula BN (Boron Nitride Molecular Formula).

jump to

dominance | appliance | Material Grade | characterization| Cases | caveat | working (of machinery) | common problems | (statistics) correlation

Boron Nitride Ceramics-Advanced Ceramic Materials-Zihao Ceramics

The main advantages of boron nitride

By choosing a boron nitride material, you will gain a range of unparalleled advantages:

Boron nitride has an extremely high thermal conductivity, especially in the direction perpendicular to the crystal layer, making it an excellent material for heat dissipation. It is also extremely heat resistant, withstanding temperatures up to 2800°C in an inert gas atmosphere.

Even at high temperatures, boron nitride maintains excellent volume resistivity and dielectric strength, making it an ideal high-temperature insulator.

The layered structure of hexagonal boron nitride gives it “self-lubricating” properties, allowing it to be used as a solid lubricant, especially in vacuum and high-temperature environments.

Boron nitride has excellent non-wetting properties to molten metals, glasses, salts and ceramics, and is therefore widely used in boron nitride crucibles and molds to prevent material adhesion.

Unlike many other hard ceramics, boron nitride is relatively easy to machine. It can be milled, turned and drilled with the same precision as graphite to create complex components.

The relatively low density of boron nitride allows for the production of lighter weight products for applications where weight is a concern.

Industry Applications

Boron nitride (BN) ceramics are widely used in electronics and semiconductor fields (as thermal interface materials, thermally conductive insulating substrates, and PBN crucibles and holders for wafer/film processing), metallurgy and material processing fields (as crucibles, melting chambers, liquid metal conveyors, and corrosion-resistant linings), high temperature and vacuum equipment fields (as thermal screens, infrared windows, and thermal shock components), mechanical lubrication and sealing fields (utilizing h-BN's solid lubrication and low friction properties), maintaining electrical insulation while increasing thermal conductivity. (used as heat-insulating screens, infrared windows, and thermal shock components), mechanical lubrication and sealing fields (utilizing the solid lubrication and low-friction characteristics of h-BBN), and improving thermal conductivity while maintaining electrical insulation, it plays an important role in aerospace, semiconductor manufacturing, optoelectronic devices, precision ceramic processing, high-temperature chemical industries, and other industries.

Available grades of boron nitride materials

Good Ceramics offers a wide range of BN product grades and formats to meet application requirements:

Hexagonal boron nitride (standard)

Boron Nitride Ceramics (Standard) is an advanced ceramic material with excellent high temperature stability, high thermal conductivity and self-lubricating properties. With a purity of ≥99%, boron nitride is ranked among the mainstream performance grades of the boron nitride series, and is extremely cost-effective. While maintaining excellent electrical insulation, it also has good chemical inertness and thermal shock resistance, suitable for high temperature, high vacuum, corrosion resistance and other extreme working conditions.

Compared with other engineering ceramics (e.g. alumina, zirconia, etc.), boron nitride combines a low coefficient of friction and excellent machinability, enabling long-term stable operation in high-temperature environments and precision machining, making it suitable for manufacturing critical components that require high-temperature insulation and lubrication.

Main features

  • High Temperature Stability: It can withstand temperatures in excess of 2000°C in an inert atmosphere or vacuum for extended periods of time, and is stable to approximately 900°C in air, making it suitable for use in extreme temperature environments.
  • Excellent electrical insulation: volume resistivity greater than 10¹³Ω-cm, high dielectric strength, to meet the high-voltage, high-temperature insulation requirements.
  • High thermal conductivity, low coefficient of thermal expansion: thermal conductivity up to 30-60W/(m-K), low coefficient of thermal expansion (about 1-2×10-⁶/K), excellent compatibility with a wide range of materials, low thermal stress, excellent thermal shock resistance.
  • Self-lubricating and low coefficient of friction: Hexagonal crystal structure imparts interlayer sliding properties that maintain lubrication even under dry friction or high temperature conditions.
  • Excellent chemical inertness: non-reactive and non-wetting to most acids, alkalis, salts and molten metals, especially suitable for metal smelting and glass formation processes.
  • Excellent machinability: Its hardness is lower than that of ceramics such as alumina, and it can be turned, milled, drilled, and other precision machining using conventional carbide tools.

typical application

  • Crucibles, insulating plates, supports in high-temperature metallurgical equipment
  • High-temperature insulation and structural components in single crystal growth furnaces and vacuum furnaces
  • Anti-stick and isolation components for handling molten metals such as aluminum and magnesium
  • Glass forming molds and anti-stick liners
  • High Voltage Electrical Insulation and Heat Dissipation Substrates
  • High-temperature bearings, seals and other self-lubricating wear-resistant parts

production and processing

Conventional boron nitride ceramics are prepared by chemical synthesis using boron trioxide (B₂O₃) and ammonia (NH₃) or urea as the main raw materials. Boron nitride powder is obtained by chemical synthesis. Depending on the specific application, molding methods such as dry pressing, isostatic pressing and extrusion can be used.

Sintering is usually done by hot pressing (1900-2100°C, nitrogen or inert gas). Sometimes small amounts of oxides are added as sintering aids to increase density.

Finished products can be directly turned, milled, drilled and other finishing processes, the surface can also be coated with ceramic coatings such as SiC, AlN and other ceramic coatings to enhance mechanical strength and oxidation resistance.

Boron nitride ceramics (high purity)

High purity boron nitride (BN) ceramics is an ultra-high purity (BN content ≥ 99.5%) advanced ceramic material with excellent thermal stability, electrical insulation, self-lubrication and chemical inertness. By strictly controlling the impurity content, the thermal conductivity and insulation reliability of the material is significantly improved, especially suitable for high temperature, high vacuum, strong corrosion and other extreme working conditions, as well as strict requirements on the purity of the semiconductor, aerospace, high-end metallurgy and other industries.

Compared to conventional boron nitride ceramics, the high purity grade offers superior electrical, thermal and chemical stability, significantly reducing the risk of impurity-induced failures, extending the service life of critical components and maintaining stable operation in extreme environments.

Main features

  • Ultra-high purity: BN content ≥ 99.5% and very low impurity content (Ca, Si, oxides, etc. total ≤ 0.5%), to ensure stable and controllable material properties.
  • Excellent thermal properties: thermal conductivity of 50 to 70W/(m-K), low coefficient of thermal expansion of about 1.0 to 1.2×10-⁶/K, excellent thermal shock resistance, suitable for rapid cycling between hot and cold conditions.
  • High Temperature Stability: Withstands temperatures in excess of 2000°C for extended periods of time in an inert atmosphere or vacuum, and is stable to approximately 850-900°C in air.
  • Excellent electrical insulation: volume resistivity >10¹⁴Ω-cm and high dielectric strength, to meet the high-voltage, high-temperature insulation requirements.
  • Self-lubricating and excellent machinability: The hexagonal laminate structure provides a low coefficient of friction, making this high-purity product easy to precision machine, allowing complex structural components to be formed using conventional carbide tools.

typical application

  • Crucibles, insulating materials and supports in pyrometallurgical and vacuum equipment
  • Anti-sticking isolation parts for molten metals such as aluminum and magnesium
  • Semiconductor power device (SiC, GaN, LED) high temperature insulation heat dissipation substrate
  • Glass forming molds and anti-stick liners
  • Powder metallurgy nozzles and corrosion-resistant parts
  • Vacuum coating equipment components such as CVD/PVD evaporation boats, high purity isolation plates, etc.
  • High temperature insulation and thermal management components for aerospace and military electronics

production and processing

High purity boron nitride ceramics are made of ultra-high purity hexagonal boron nitride powder by hot pressing process. The sintered high purity boron nitride has moderate hardness and can be precision machined by turning, milling, drilling and other processes.

Pyrolytic Boron Nitride Ceramics (PBN)

Pyrolytic Boron Nitride (PBN) ceramics are high purity (≥99.99%) hexagonal boron nitride materials prepared using the Chemical Vapor Deposition (CVD) process. This unique deposition method produces a binder-free, impurity-free material with a dense, uniform microstructure, superior purity and excellent anisotropic properties.

PBN offers higher purity, excellent gas tightness, and a dense, smooth surface than hot-pressed boron nitride (HPBN). It can be molded directly into desired shapes during the deposition process, making it particularly suitable for ultra-high vacuum, high-purity material processing, and contamination-sensitive semiconductor manufacturing environments.

Main features

  • Ultra-high purity: BN content ≥99.99%, almost free of oxygen, carbon, metal and other impurities, suitable for use in extremely clean working conditions.
  • High density and gas tightness: CVD deposited structures are free of pores and microcracks and have extremely low gas permeability for use in high vacuum environments.
  • Excellent thermal stability: withstands long-term operation in excess of 2000°C in a vacuum or inert atmosphere, and is stable to approximately 900°C in air.
  • Excellent electrical insulation: volume resistivity > 10⁴ Ω-cm and high dielectric strength even at high temperatures.
  • Anisotropic thermal properties: high thermal conductivity (up to 30-60 W/(m-K)) parallel to the deposition layer and low thermal conductivity in the perpendicular direction, favoring specific thermal management designs.
  • Smooth surfaces for direct molding: Dense, smooth surfaces on deposited parts eliminate the need for post-processing and meet the needs of most applications. Complex shapes such as crucibles and tubes can be deposited directly.

typical application

  • High-purity crucibles and evaporation boats for semiconductor equipment such as MBE (molecular beam epitaxy) and MOCVD
  • Isolators and guide parts for high vacuum coating equipment
  • Melting and evaporation vessels for high-purity metals and alloys
  • Evaporation source components for optical thin film production
  • Ultra-clean, high-temperature racks for high-end electronics production
  • High temperature insulation components for aerospace and military applications

production and processing

Pyrolytic boron nitride ceramics are produced by chemical vapor deposition (CVD) process:

  1. Deposited materials: boron trichloride (BCl₃) and ammonia (NH₃)
  2. Process conditions: The reaction is carried out in a graphite mold at a high temperature of 1800~2000°C. BN is deposited in molecular form on the inner wall of the mold, gradually forming a dense structure.
  3. Direct molding: The CVD process allows for direct deposition molding to the shape of the mold, eliminating the need for sintering and adhesives, thus preventing secondary contamination.
  4. Post-processing: Most PBN parts are ready for immediate use. If adjustments are needed, they can be precision machined or surface treated.

Composite Boron Nitride Ceramics

Composite boron nitride ceramics are a class of engineering ceramic materials based on boron nitride (BN) as a matrix, reinforced or modified with other ceramics or metal compounds such as alumina (Al₂O₃), aluminum nitride (AlN), silicon carbide (SiC), zirconium oxide (ZrO₂) and boron oxide glass. The design goal is to significantly improve mechanical strength, oxidation resistance, wear resistance and thermal conductivity while maintaining BN's excellent high temperature insulation, self-lubrication and chemical inertness.

Compared with pure BN ceramics, composite boron nitride has excellent high-temperature strength, density and environmental adaptability to meet the harsh operating conditions of metallurgy, semiconductor, vacuum coating, aerospace and other industries.

Main features

  • Customizable properties: Mechanical properties, thermal properties and chemical stability can be optimized by selecting different types and ratios of reinforcing phases to suit specific operating conditions.
  • High Temperature Stability and Insulation: Most composite BN ceramics can withstand temperatures in excess of 1800-2000°C in an inert atmosphere while maintaining excellent electrical insulation (volume resistivity > 10¹² Ω-cm).
  • Enhancement of mechanical properties: Adding Al₂O₃, ZrO₂ or SiC can increase the bending strength by 2-3 times, improve the brittleness, and increase the impact resistance.
  • Improvement of antioxidant performance: Some composite phases (e.g., Al₂O₃ and B₂O₃ glass phases) can form a dense protective film on the surface in a high-temperature oxidizing environment, which can effectively retard the oxidation of BN.
  • Adjustable thermal conductivity: By introducing high thermal conductivity materials such as AlN, SiC, etc., the thermal conductivity of traditional BN can be increased from 30-60W/(m-K) to 80-150W/(m-K) to meet the demand for high-power heat dissipation.
  • Machinability maintained: BN ceramics retain their excellent machinability after composite application, allowing precision machining such as turning, milling and drilling with conventional carbide tools.

typical application

  • High-temperature anti-sticking and insulating parts for metal melting and casting equipment
  • High-temperature molds, glass molding gaskets
  • Insulating heat dissipation substrate for high power semiconductor devices (composite high thermal conductivity phase)
  • Vacuum coating equipment evaporation boat and isolation bracket
  • High-temperature bearings, sliders, wear-resistant guides (composite reinforced phase to improve strength and wear resistance)
  • Aerospace high temperature insulation and structural components

production and processing

Raw material preparation: Select high purity BN powder and reinforcing phase powder (e.g., Al₂O₃, AlN, SiC, ZrO₂) and mix them well according to the formula ratio.

Molding process: commonly used dry pressure, isostatic pressure, slurry molding, according to the complexity of the product to choose different methods.

Sintering methods: hot pressing (HP), hot isostatic pressing (HIP) or reaction sintering; temperatures typically 1700-2000°C in nitrogen or inert gas atmosphere.

Post-treatment: Machined to final shape. Surface coatings (e.g. SiC, Al₂O₃) can be added as required to further enhance oxidation and wear resistance.

Key Properties of Boron Nitride

Zhihao Ceramics offers a wide range of boron nitride materials for customers to choose from. The values below are typical material properties and may vary depending on product configuration and manufacturing process. Please feel free to contact us for more details.

realm GCBN-HBN1 GCBN-HBN2 GCBN-PBN GCBN-B GCBN-C GCBN-D GCBN-E GCBN-S2 GCBN-S3
Main Composition BN≥99% (standard) BN≥99.5% (high purity) BN≥99.99% Boron Nitride + Zirconium + Aluminum Boron Nitride + Silicon Carbide Boron Nitride + Zirconia Boron Nitride + Aluminum Nitride silicon nitride silicon nitride
Density (g/cm3) 2.0-2.3 ≥2.0 1.95-2.22 2.25-2.35 2.40-2.50 2.80-2.90 2.80-2.90 2.55-2.65 2.75-2.85
Oxygen content (%) 0.46 <0.3 <0.1 - - - - - -
Porosity (%) 2.6 <2.0 dense - - - - - -
Richter hardness HL ≥330 ≥330 - - - - - - -
Three-point bending strength (MPa) thirty-eight 40-50 80 65 85 115 120 220 320
Compressive strength (MPa) 110-150 120-160 - 110 130 225 220 420 480
Coefficient of thermal expansion (×10-⁶/K) 2.0-2.8 2.0-2.5 2.0 (a)/ 2.6 (c) 2.0 2.8 3.5 2.8 2.7 2.7
Thermal conductivity (W/m-K) 30-50 50 82.3 (200°C)/55.3 (900°C) 30 30 20 80 40 40
Maximum working temperature (℃) Air 900 / Vacuum 2100 / Inert 2300 Air 900 / Vacuum 2100 / Inert 2300 2000+ Air 1000 / Vacuum 1800 / Inert 1800 Air 1000 / Vacuum 1800 / Inert 1800 Air 1000 / Vacuum 1800 / Inert 1800 Air 1000 / Vacuum 1800 / Inert 1800 Air 1000 / Vacuum 1800 / Inert 1800 Air 1000 / Vacuum 1800 / Inert 1800
Room temperature resistivity (Ω-cm) >10¹⁴ >10¹⁴ 10¹⁵ >10¹³ >10¹² >10¹² >10¹³ >10¹³ >10¹³
typical application Powder metallurgy, metal evaporation crucibles, insulators High-temperature insulating parts for semiconductor equipment Vacuum coating, semiconductor heaters, insulating components Powder metallurgy, high temperature bracket powder metallurgy Metal Casting Molds powder metallurgy powder metallurgy powder metallurgy

Boron Nitride Product Application Cases

Good Ceramics' Boron Nitride ceramic products, especially in the form of hexagonal Boron Nitride (h-BN) and Pyrolytic Boron Nitride (PBN), offer excellent thermal conductivity, superior electrical insulation, chemical inertness, low hardness for easy machining, and excellent high temperature stability. These properties make our BN parts suitable for a wide range of industries. Common applications for our Boron Nitride products include:

High purity PBN crucibles are used in semiconductor crystal growth and metal melt processing where chemical inertness and contamination control are critical.

Heat sinks, thermal interface pads and cooling supports utilize the thermal conductivity of boron nitride while maintaining electrical insulation.

Utilizes the dielectric strength of BN to provide insulating bases, feedthroughs, and substrates for high voltage and high temperature electronic equipment.

Evaporation boats, liners and fixtures made of BN are suitable for CVD/epitaxy and wafer processing due to low contamination and high purity.

Tubes, rings, plates and retorts for high-temperature furnaces requiring thermal shock resistance and chemical stability.

Precision machined BN tubes, rods, gaskets and rings for laboratory, vacuum and metallurgical applications.

Slides, seals and bearings benefit from the solid lubrication properties of h-BN at high temperatures.

Pipe liners, nozzles and contact parts are exposed to corrosive or reactive environments where metal parts may fail or contaminate the product.

Thermal isolation, vacuum feedthroughs and structural components are used where light weight, thermal stability and resistance to outgassing are important.

CNC machined, close tolerance BN components (substrates, spacers, custom fixtures) designed for demanding industrial and research applications.

BN003
202
0102-1
2107011
030
62b5b349-5059-4d1a-8344-a41412df52c9
083
0041-1

Precautions for the use of boron nitride ceramics

Following these precautions when working with boron nitride ceramics will help maximize the performance, stability, and longevity of boron nitride products in demanding industrial applications.

While h-BN is stable in inert or vacuum environments up to 2000°C (PBN is stable at temperatures up to 3000°C), oxidation resistance is limited to temperatures around 850-1000°C in air.

BN ceramics, while softer than many ceramics, are still brittle and can break under sudden mechanical loads or impacts.

To avoid contamination (especially with semiconductor grade PBN), use clean gloves and specialized handling equipment.

BN is chemically inert to most acids, alkalis and molten metals, but strong oxidizing agents at high temperatures may damage the surface.

BN Components may undergo dimensional changes at elevated temperatures; precision fits should account for thermal expansion and potential shrinkage.

For components, select a joining technique (mechanical fastening, high-temperature adhesives, or brazing to a compatible metal) that matches the thermal and mechanical characteristics of the BN.

Prior to installation, keep components in a dry, dust-free environment to maintain surface integrity and prevent contamination.

Processing of boron nitride ceramics

A unique advantage of boron nitride is its relatively low hardness (~2 on the Mohs scale for h-BN), which makes it easier to machine than many other ceramics. Standard carbide or high-speed steel tools can be used for h-BN, while harder BN composites may require diamond grinding, CNC machining, laser cutting, or ultrasonic machining to ensure accuracy and surface finish.

With a full range of state-of-the-art processing equipment and extensive technical expertise, Chiho Ceramics provides end-to-end solutions - from material selection and design optimization to precision machining and assembly - to ensure that high-quality, high-performance boron nitride ceramic products meet the most demanding applications. requirements.

Ceramics - CNC machining

CNC grinding and milling

CNC milling, turning and grinding to micron tolerances.

x002

Grinding and polishing

Surface polishing results in smooth surfaces and optical grade surfaces.

Laser processing of ceramic substrates

Ceramic Laser Cutting

For laser drilling and cutting of complex geometries.

Metal and Ceramic Brazed Assemblies - 600x600

Metallization and welding

Metallization (Mo/Mn, W) for ceramic-to-metal brazing.

common problems

Boron nitride is a synthetic ceramic material composed of boron and nitrogen atoms. It is a crystal and exists in various forms such as hexagonal boron nitride, cubic boron nitride and pyrolytic boron nitride.

Yes, boron nitride is a compound with the chemical formula BN. It is a stable binary compound of boron and nitrogen.

The hardness of boron nitride depends on its crystal structure. Hexagonal boron nitride (h-BN) is similar to graphite and is soft. Cubic boron nitride (c-BN), on the other hand, has a structure similar to diamond, making it one of the hardest materials known to man. Its hardness results from the strong covalent bonds in its crystal lattice.

Hexagonal boron nitride is an excellent electrical insulator. It has a high electrical resistance and is widely used in areas requiring high temperature insulation.

Hexagonal boron nitride is usually produced by reacting boric acid with a nitrogen source such as urea at high temperatures. Pyrolytic boron nitride is produced by chemical vapor deposition (CVD), in which a mixture of boron and nitrogen compounds is deposited on a graphite substrate.

Yes, boron nitride is classified as a high performance ceramic material, specifically an advanced ceramic.

Yes, boron nitride is a reticulated covalent compound due to the fact that the atoms in its crystal structure are bonded together by strong covalent bonds. This is reflected in its layered structure similar to graphite (hexagonal lattice) or its cubic structure similar to diamond.

No, boron nitride is not a polymer. It is an inorganic crystalline solid with a well-defined crystal structure, not a long chain of molecules made up of repeating substituents.

Related Products

aluminum nitride

Aluminum oxide ceramic substrates

silicon nitride

Black Aluminum Oxide Substrate

Advanced Ceramics Manufacturing Specialist

Why Choose Good Boron Nitride

  • High Purity: Up to 99.99% for semiconductor grade applications.
  • Advanced technology: hot pressing and CVD to obtain different grades of BN.
  • Customized solutions: from standard crucibles to complex precision parts.
  • Precision machining: CNC system, small tolerance, smooth surface.
  • Strict quality control: ensure the consistency and reliability of each batch of products.
  • End-to-end service: from design to final assembly, tailored to your application.

Contact today we

Ready to bring your ceramic designs to life?
Contact Chiho Ceramics for customized ceramic processing solutions that meet the highest standards for your application.