| 摘要 |
<p>The invention relates to a sintered compact for use in an ultrahard tool having high resistance to heat and wear, outstanding thermal conductivity and thermal shock resistance property at elevated temperature, and suitable for high-speed cutting, and to a method for producing the same. A powder mixture comprising 20-80 volume % high pressure form boron nitride powder, the residual part consisting of Al2O3 powder or a compound ceramic powder principally comprising Al2O3 powder and also containing carbides, nitrides of IVb, Vb, VIb metals of the periodic table, mutual solid solution thereof or admixture thereof, is sintered as it stands or after pressing under a high pressure and a high temperature so that Al2O3 of the compound ceramic constitutes a continuous phase in the structure of the sintered compact, and the half width of (116) in the X-ray diffraction of CuK alpha ray of Al2O3 crystals in the structure constituting the continuous phase is within the range from 0.200 deg. to 0.600 deg., thereby enabling to obtain a sintered compact for use in a tool having the aforesaid high properties.</p> |
