| 摘要 |
PROBLEM TO BE SOLVED: To improve breakage resistance without deteriorating wear resistance and to obtain a TiCN-base cermet alloy excellent in cutting life by specifying respective values of saturation magnetic flux density and coercive force among material characteristics and further specifying hardness and crack length, respectively. SOLUTION: In a TiCN-base cermet alloy, atmosphere at the time of manufacture and sintering temp. are regulated, respectively, and the saturation magnetic flux density (4πσ) and coercive force (Hc) of the material are regulated to (4 to 22)μTm<3> /kg and 100-200, respectively. Further, hardness and crack length are regulated to 91.0-91.7 by HRA and <=180μm, respectively. At this time, the limitation of saturation magnetic density to >=4 indicates that carbon content in a binding phase is in a high carbon region, and <=22 is used for convenience sake to show the extent causing no free carbon phase because there are causes where the content of the binding phase is high or low. Coercive force is regulated to 100-200 because the thickness of the binding phase becomes too large when coercive force is less than 100, and, when it exceeds 200, the thickness of the binding phase becomes too small. Within the ranges of both properties mentioned above, the breakage resistance and wear resistance of a tip can be improved.
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