| 摘要 |
<p>A cBN sintered body superior in chipping resistance. The cBN sintered body is a sintered body in which cBN particles are bonded through a bonding phase. The bonding phase has a two-dimensionally continuous structure. The bonding phase comprises at least one kind selected from the group consisting of (a) carbide, nitride, carbonitride, or boride of a 4a-, 5a-, or 6a-group transition metal in the periodic table; (b) nitride, boride, or oxide of Al; (c) at least one kind of carbide, nitride, carbonitride, and boride of Fe, Co, or Ni; and (d) a mutual solid solution of those. The percentage of cBN content is 45 to 70% in volume. The bonding phase has the thickness of which the average value is 1.5 mu m or less and the standard deviation is 0.9 mu m or less with the cBN particles having an average particle size of 2 to 6 mu m inclusive. The bonding phase has the thickness of which the average value is 1.0 mu m or less and the standard deviation is 0.7 mu m or less with the cBN particles having an average particle size of not less than 0.01 mu m and less than 2.0 mu m.</p> |
