01
Boron Nitride: Versatile Material for Industrial Use
High thermal stability
h-BN can withstand 2000°C in an inert atmosphere and is stable up to 900°C in an oxidative environment;
c-BN does not convert to h-BN below 1400°C.
Thermal properties
h-BN has better thermal conductivity than aluminum oxide (along the c axis: 400 W/m·K, perpendicular to the c axis: 30 W/m·K);
Low thermal expansion coefficient (h-BN: along the c axis -2.7×10⁻⁶/°C, perpendicular to the c axis 38×10⁻⁶/°C);
Mechanical properties
h-BN has low hardness (Mohs hardness ~2) and strong machinability; c-BN hardness is second only to diamond;
h-BN has excellent thermal shock resistance (due to low elastic modulus).
Electrical properties
h-BN is a high-quality insulator (resistivity > 10¹⁴ Ω·cm, dielectric constant ~4);
c-BN is a wide bandgap semiconductor (bandgap width ~6.4 eV);
Chemical inertness
Resistant to erosion from molten metals (such as aluminum, copper), does not react with acids/bases (except for concentrated sulfuric acid and molten alkali);
Thermal properties
h-BN has better thermal conductivity than aluminum oxide (along the c axis: 400 W/m·K, perpendicular to the c axis: 30 W/m·K);
Low thermal expansion coefficient (h-BN: along the c axis -2.7×10⁻⁶/°C, perpendicular to the c axis 38×10⁻⁶/°C);
Mechanical properties
h-BN has low hardness (Mohs hardness ~2) and strong machinability; c-BN hardness is second only to diamond;
h-BN has excellent thermal shock resistance (due to low elastic modulus).
Electrical properties
h-BN is a high-quality insulator (resistivity > 10¹⁴ Ω·cm, dielectric constant ~4);
c-BN is a wide bandgap semiconductor (bandgap width ~6.4 eV);
Chemical inertness
Resistant to erosion from molten metals (such as aluminum, copper), does not react with acids/bases (except for concentrated sulfuric acid and molten alkali);
Electronics and Semiconductor
Heat dissipation substrate: h-BN ceramics are used as insulating heat sinks for high-power LEDs and RF devices;
Semiconductor equipment: PBN crucibles are used for GaAs and GaN single crystal growth;
Microwave window materials: h-BN has good transparency and is used in radar and plasma devices;
Semiconductor equipment: PBN crucibles are used for GaAs and GaN single crystal growth;
Microwave window materials: h-BN has good transparency and is used in radar and plasma devices;
High-temperature and Metallurgy
Continuous casting: h-BN as a separating ring to prevent molten steel from sticking;
Thermocouple protection tube: resistant to molten aluminum and magnesium corrosion;
Mechanical Tools
Lubricants: h-BN powder is used for high-temperature lubrication of gears and bearings (as a substitute for graphite in oxidative environments);
Superhard Tools: c-BN cutting tools for machining quenched steel and cast iron.
h-BN has excellent thermal shock resistance (due to low elastic modulus).
Neural energy and Aerospace
Lubricants: h-BN powder is used for high-temperature lubrication of gears and bearings (as a substitute for graphite in oxidative environments);
Superhard Tools: c-BN cutting tools for machining quenched steel and cast iron.
