PRODUCTION OF BORON NITRIDE

PURPOSE:To rapidly produce BN having a high content of c-BN without using special raw material or device by using a plasma-jet process in the production of BN by means of a CVD method. CONSTITUTION:A gaseous mixture of B2H6, NH3, H2, Ar, etc., is used as the raw gaseous material in the CVD method. A voltage is impressed between electrodes 3 and 4 from a DC power source 6 to generate an arc, and the gas is converted to plasma. Since the temp. of plasma becomes heat up to about 5000 to 20,000 deg.K, the gas is rapidly expanded, and a plasma jet 7 is formed. The distance between the electrode 4 and a substrate 5 is preferably controlled to about 5 to 50mm, and the substrate 5 is appropriately heated at 200 to 700 deg.C. Consequently, BN contg. c-BN and h-BN is deposited on the substrate 5. The c-BN having high heat conductivity can be utilized as a radiating substrate. Since the c-BN has a high hardness and the h-BN with lubricity is together contained, the BN-coated substrate 5 can also exhibit an excellent effect as a sliding member.