(1) High temperature resistance: h-BN ceramics have excellent heat resistance, withstanding high temperatures of around 2000℃; in air atmosphere, the service temperature can also reach 900℃.
(2) Thermal conductivity: It has excellent unidirectional thermal conductivity. At room temperature, h-BN ceramics have high thermal conductivity in the parallel direction, with a thermal conductivity of over 60 W/(m·K).
(3) Low coefficient of thermal expansion: Approximately (2.0-6.5)×10⁻⁶/℃.
(4) Excellent thermal shock resistance: Its hot-pressed products will not crack even after hundreds of cycles under the condition of air cooling from 1200℃ to room temperature.
(5) Good electrical insulation: At room temperature, its resistivity can reach 10¹⁶-10¹⁸ Ω·m; at 1000℃, the resistivity in the vertical direction reaches 3×10⁷ Ω·m, and the resistivity in the parallel direction is 3×10⁹ Ω·m. The breakdown voltage at room temperature is 30-40 kV/mm, which is twice that of alumina ceramics.
(6) Good dielectric properties: The dielectric constant in the vertical direction is 5.12, and that in the parallel direction is 3.49. Moreover, the dielectric loss is low, being (2-8)×10⁻⁴, and it is transparent to infrared rays and microwaves.
(7) Corrosion resistance: h-BN ceramics are very stable in chemical properties. They neither wet nor react with most molten metals (such as steel, Al, Fe, Ge, Bi, Cu, Ni, Zn, etc.), glass, and salts, and have strong resistance to erosion by acids, alkalis, molten metals, and glass slags.