| 摘要 |
PROBLEM TO BE SOLVED: To provide cemented carbide which exhibits high cutting performance even under severe cutting conditions, and has excellent oxidation resistance and impact resistance. SOLUTION: The cemented carbide is obtained by bonding the spaces of hard phases 4 each consisting of 60 to 85 vol.% WC particles having a mean particle diameter of 0.2 to 0.8μm and 5 to 30 vol.%βphase particles 3 each consisting of the carbide, nitride or carbonitride of at least one kind selected from the group 4a, 5a and 6a metals in the Periodic Table and having a mean particle diameter of 1.2 to 3μm with 5 to 20 vol.% bonding phases 5 essentially consisting of at least one kind selected from iron group metals. The ratio between the density Db of a bulk body measured by a gas replacement method and the density Dp of the powder after the pulverization of the bulk body into a size so as to pass through a # 200 mesh, Db/Dp is≥0.95. Also,≥50% of bonding phase pools 6 with dimensions of≥0.7μm present in the structure are present in a state of being contacted with theβphase particles 3. COPYRIGHT: (C)2004,JPO&NCIPI
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