| 摘要 |
PURPOSE:To obtain a cubic boron nitride sintered body for tools combining sufficient hardness, strength and toughness by forming it from refractory metal compounds of specified ratios of C-BN, VIII group metals and Al as well as carbides, nitrides, carbon nitrides or the like. CONSTITUTION:This is a sintered body for tools constituted of refractory metal compounds of 30 to 80 vol.% C-BN and the balance VIII group metals and Al as well as one or more kinds among the carbides, nitrides or carbon nitrides of IV a, V a and VI a group metals and, if required, furthermore incorporated with the oxides of II a, II b, III a, IIIb, IVa, IV b and V a group metals such as Al2O3 and is suitable for the cutting of hardened steel having high hardness or the like. As the above sintered body, the one contg., by weight, 20 to 70% refractory metal compounds, 5 to 30% VIII group metals and <= 5% Al, and furthermore as for the VIII group metals and Al, the total content is regulated to 5 to 45% and they are preferably present as intermetallic compounds at least partially. The above sintered body can be obtd. by densely mixing the mixed powder of a reinforcing material contg. the VIII group metals, Al, refractory metal compounds or the like with C-BN powder in the prescribed ratios and integrating this mixed powder at 1200 deg.C and >= 40 kb. |
