| 摘要 |
FIELD: chemistry.SUBSTANCE: invention relates to production of superhard composite material based on cubic boron nitride (CBN) in the presence of synthesis catalysts and additional reactants in a high-pressure chamber. The invention can be used to make cutting parts of a machining tool that are in direct contact with the workpieces. The composite polycrystalline material based on CBN is obtained via secondary synthesis of CBN powder from hexagonal boron nitride powder in a high-pressure chamber in the presence of a catalyst in form of a boride or nitride of an alkali or alkali-earth metal. To this end, CBN powder, obtained in advance using nitride catalysts, is mixed with a boride catalyst. If CBN powder obtained using boride catalysts is used, nitride catalysts are used for secondary synthesis. To neutralise residual reaction products and bind said products in a matrix into a harder phase, aluminium metal powder is added to the charge mixture and mechanical alloying is carried out. After mechanical alloying of CBN particles by mixing and rubbing them with aluminium, powdered carbides of refractory metals are added to the mixture, followed by pressing and subjecting the workpiece to pressure and temperature of 5-5.5 GPa and 1300-1600°C for 15 s to 20 min.EFFECT: high chemical wear resistance and heat resistance of the composite.25 cl, 6 ex |
