What are the material properties of boron nitride ceramics?

Boron nitride has chemical corrosion resistance, and is not attacked by inorganic acid and water. The boron-nitrogen bond is broken in hot concentrated alkali. Oxidation begins in air above 200℃. The melting point is 3000℃, and sublimation begins when it is slightly lower than 3000℃. It begins to decompose at about 2700℃ in vacuum. Slightly soluble in hot acid, insoluble in cold water, density greater than 2.0, bending strength 30Mpa.

The service temperature in oxidizing atmosphere is not higher than 900℃, but it can reach 2800℃ in inactive reducing atmosphere, but the lubrication performance is poor at room temperature. Most properties of boron carbide are better than those of carbon materials. For hexagonal boron nitride: low friction coefficient, good high temperature stability, good thermal shock resistance, high strength, high thermal conductivity, low expansion coefficient, high resistivity, corrosion resistance, microwave or infrared transmission.