| 摘要 |
PROBLEM TO BE SOLVED: To obtain an alloy withstanding high speed cutting for a long time and also applicable to dry cutting by composing a hard layer of a compd. contg. the oxide of Zr and/or Hf, controlling the average particle size of the compd. in a region to a depth from the surface to a specified range and composing a coating layer of a single phase or a multiple phase consisting of the oxides or the like of the group 4a, 5a and 6a metals in the Periodic Table. SOLUTION: A coating layer is formed on the surface of a base material composed of bonding layer metal consisting of WC and iron group metal and a hard layer. The hard layer is composed of a compd. contg. at least one kind among the oxides, carbides, nitrides and carbonitrides of Zr and/or Hf, the average particle size of the compd. is controlled to 0.02 to 0.5μm in the region to a depth of 50μm from the surface of the base material and to 1.0 to 5.0μm in the region to a depth of 150μm, and the coating layer is composed of a single layer of at least one kind among the oxides, carbides, nitrides, borides of the group 4a, 5a and 6a metals in the Periodic Table and aluminum oxide or a multiple phase thereof. Its high temp. toughness, hardness and plastic deformation resistance remarkably improve.
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