SUPER HARD ALLOY AND CUTTING TOOL USING SAME

摘要

Disclosed are a super hard alloy which has high thermal diffusivity and excellent wear resistance, and a cutting tool which comprises a base member that is composed of the super hard alloy. Specifically disclosed is a WC-based super hard alloy wherein hard phases that are mainly composed of WC particles are bonded by a binder phase that is mainly composed of Co. The WC-based super hard alloy is used for a cutting tool. The binder phase is substantially configured of Co or Co and Ni, and the total content of Co and Ni is 4.5-15% by mass (inclusive). The average particle diameter of the WC particles in the super hard alloy is 0.4-4 µm (inclusive), and when the average particle diameter of the WC particles is represented by x (µm), the thermal diffusivity X (cm2/sec) satisfies the following relation: X > 0.055x + 0.238. The super hard alloy can additionally contain one or more elements selected from among Cr, Ta, Nb, Zr and Ti in an amount of 0.05-5% by mass in total.