| 摘要 |
PROBLEM TO BE SOLVED: To provide a hard metal alloy of which the hardness and thermal conductivity in a high-temperature region of >=500 deg.C in particular are high, and also to provide a cutting tool having excellent wear resistance, plastic deformation resistance and tool fracture resistance even in machining of the hard machining materials such as stainless steel. SOLUTION: The hard metal alloy 1 has a structure which consists of a tungsten carbide phase 2, a solid-solution phase 3 composed of the carbides, nitrides and carbonitrides of at least two metals selected from the group consisting of the group IVa, Va, and VIa metals of the periodic table, and a binding phase 5 containing at least one iron family metal. Moreover, this hard metal alloy contains, as the above solid-solution phase 3, at least a Zr-Nb solid-solution phase 7 containing Zr and Nb, and further the ratio of the average grain size d2 of the Zr-Nb solid-solution phase 7 to the average grain size d1 of the tungsten carbide phase 2, d2 /d1 , is 0.5 to 2. |
