China Hexagonal Boron Nitride
Feb 28, 2022
Boron nitride is chemically resistant to attack by inorganic acids and water. Boron - nitrogen bonds are broken in hot concentrated alkali. Above 1200℃ begins to oxidize in air. Melting point is 3000℃, slightly lower than 3000℃ begins to sublimate. Decomposition begins at about 2700℃ in vacuum. Slightly soluble in hot acid, insoluble in cold water, relative density 2.25. The compressive strength is 170MPa. The maximum operating temperature is 900℃ in oxidizing atmosphere and 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: very low friction coefficient, high temperature stability, good thermal shock resistance, high strength, high thermal conductivity, low expansion coefficient, high resistivity, corrosion resistance, microwave or infrared penetration.
