| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a cemented carbide which is suitable for a tool raw material and achieves reduction in uneven wear of a tool thereby contributing to the extension of the life of the tool. <P>SOLUTION: The cemented carbide is formed by bonding between tungsten carbide (WC) particles with a bonding phase mainly composed of cobalt (Co), and the average grain size of the WC particles is 0.1-0.5 μm, and the bonding phase contains 5 to 12 mass% of Co. The average thickness of the bonding phase is 0.14 μm or smaller. The ratio of the bonding phases each having a thickness of 0.5 μm or more is 0.15% or less of the whole bonding phase. In the cemented carbide, the bonding phases (black-colored parts in Fig.1(I)) exist between micro WC particles (gray-colored parts in the same figure) thinly and evenly, and do not agglomerate micro-wisely and do not exist unevenly. Uneven wear can be suppressed and working superior in positional accuracy can be performed over a long-period of time when the cemented carbide having the microstructure like this is utilized for a micro-drill. <P>COPYRIGHT: (C)2013,JPO&INPIT |
