What are the properties of boron nitride?

Table of Contents

1. Introduction
2. Structure and Composition
3. Physical Properties
4. Thermal Properties
5. Electrical Properties
6. Chemical Properties
7. Applications
8. Baoran Chemical Company Solutions
9. References

Introduction

Boron Nitride (BN) is a unique material with a variety of properties, making it indispensable in several industrial and scientific applications. It consists of boron and nitrogen atoms arranged in distinct structures, leading to different forms each with its own set of properties.

Structure and Composition

Boron nitride exists in several polymorphs, but the most common are hexagonal boron nitride (h-BN) and cubic boron nitride (c-BN). h-BN, analogous to graphite, consists of layered structures, while c-BN resembles the diamond cubic crystal structure.

Physical Properties

Boron nitride exhibits several key physical properties:

• Density: h-BN has a density of approximately 2.1 g/cm³, whereas c-BN has a density of 3.48 g/cm³.
• Hardness: c-BN is second only to diamond with a hardness of 48 GPa (Vickers). h-BN is much softer, similar to graphite.
• Color: h-BN is generally white, while c-BN is typically yellow to brown.

Thermal Properties

Boron nitride exhibits exceptional thermal characteristics:

• Thermal Conductivity: h-BN demonstrates high thermal conductivity along its planes, up to 200 W/m·K, while c-BN is about 740 W/m·K.
• Thermal Stability: h-BN remains stable up to 1000°C in oxygen-rich environments, whereas c-BN can withstand higher temperatures, around 1800°C.
• Thermal Expansion: The coefficient of thermal expansion for h-BN is around 1.7 × 10^-6 /°C in-plane.

Electrical Properties

The electrical properties of boron nitride vary considerably with its form:

• Insulating Properties: h-BN is an excellent insulator with a high electrical resistance of about 10¹⁶ Ω·m.
• Bandgap: h-BN has a wide bandgap of approximately 5.9 eV, contributing to its insulating capabilities.

Chemical Properties

Boron nitride is chemically inert and resistant to most chemicals, including acids and alkalis. This property makes it valuable for applications that require material stability under harsh conditions.

Applications

Due to its unique properties, boron nitride finds its use in various applications:

• Lubricants: h-BN serves as a lubricant because of its layered structure similar to graphite.
• Abrasives: c-BN is used as an ultra-hard abrasive in cutting and tooling applications.
• Electronics: Utilized in high-temperature electronics and insulating substrates due to its thermal and electrical properties.
• Coatings: Protective coatings in metal processing and aerospace applications.

Baoran Chemical Company Solutions

Baoran Chemical Company is a key player in the industry, offering advanced boron nitride solutions:

• Product Range: The company provides a diverse range of BN powders and compound solutions tailored to specific industrial needs.
• Customization: Baoran Chemical offers customized formulations to meet unique thermal and chemical requirements.
• Quality Assurance: Their products undergo rigorous testing to ensure consistency and performance.

References

1. Chubarov, M., et al. Synthesis and properties of hexagonal boron nitride. Journal of Material Chemistry (2020).
2. Smith, J. Thermal and electrical properties of cubic boron nitride. Advanced Materials (2019).
3. Baoran Chemical Company Website, https://www.baoranchemical.com