| 摘要 |
PURPOSE:To obtain a sintered hard alloy improved in machining characteristics to a greater extent, by specifying the saturation magnetic charge of a sintered hard alloy of Ti and double carbide of Ta, Mo, and W and also specifying the sum total of nonmetallic elements/the sum total of metallic elements (atomic ratio) in a hard dispersed phase. CONSTITUTION:A sintered hard metal of Ti and double carbide of Ta, Mo, and W having, by atomic ratio, 0.5-0.9 Ti and 0.3-0.7 C and N as card dispersed phase and having 2-40wt% Ni and Co as binding metal phase is provided, where the saturation magnetic charge for measuring the amount of high-m.p. metal in the form of solid solution in the sintered hard metal is 20-90% of that based on the assumption that the binding metal phase consists of pure Ni and Co. Moreover, the Z value in the hard dispersed phase, that is, the sum total of nonmetallic elements/the sum total of metallic elements(atomic ratio) is 0.90-100. Accordingly, in the alloy of this invention, the hard dispersed phase is highly refined, the Z value is high, and the high-m.p. metal sufficiently enters into solid solution in the binding metal phase for strengthening, so that thermal fatigue resistance is remarkably improved.
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