| 摘要 |
PROBLEM TO BE SOLVED: To remarkably enhance strength and toughness by nonuniformly dispersing crystal phases composed of carbide, a nitride or a carbon nitride, and dotting coagulated parts where hard phase particles of these densely exist in cermet. SOLUTION: In cermet which is composed of a hard phase composed of a carbonitride of Ti, carbide, a nitride and a carbonitride of No. 4a, 5a and 6a groups of a periodic table and a bonding phase 4 containing iron group metal and whose atomic ratio N/(C+N) is 0.4 to 0.7, the hard phase is composed of a first B1 type crystal 1 composed of a core part which is mainly composed of carbide, a nitride or a carbonitride of a No. 4a group element of a periodic table and whose particle diameter is not more than 1μm and a peripheral part mainly composed of carbide, a nitride or a carbonitride of No. 5a and 6a group elements of a periodic table, a second B1 type crystal 2 composed of a core part whose particle diameter is larger than 1μm and a peripheral part and a third B1 type crystal 3 in which a core part does not exist and which is mainly composed of carbide, a nitride or a carbonitride of No. 5a and 6a group elements of a periodic table. The first and third B1 type crystals are dotted as coagulated parts A having the size of 10 to 150μm.
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