Coated CBN sintered body
AssigneeTungaloy Corporation
InventorsTakahide Kudoh, Naohiro Kagawa, Takashi Umemura
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Abstract
A coated cBN sintered body has excellent wear resistance, fracture resistance, adhesiveness between a substrate and a coating, and a tool life of which is elongated as compared with conventional cBN sintered bodies. The coated cBN sintered body has a cBN sintered body substrate and a coating coated on the surface thereof. The cBN sintered body includes 76 to 90% by volume of cBN, and 10 to 24% by volume of a binder phase and inevitable impurities. An average grain size of cBN is 0.5 to 5.0 μm, an average value of the thickness of the binder phase is 0.05 to 0.8 μm, and the standard deviation of the thickness of the binder phase is 0.8 μm or less.
Claims25
A coated cBN sintered body which comprises a cBN sintered body substrate and a coating coated on the surface thereof, wherein
- the cBN sintered body comprises 76 to 90% by volume of cBN and 10 to 24% by volume of a binder phase and inevitable impurities,
- an average grain size of the cBN is 1.5 to 4.0 μm,
- an average value of a thickness of the binder phase is 0.05 to 0.8 μm, and
- a standard deviation of the thickness of the binder phase is 0.8 μm or less;
- wherein the cBN is a sintered product of a mixture comprising
- coarse particle cBN powders having an average particle size of exceeding 2.0 μm and 7.0 μm or less, and
- fine particle cBN powders having an average particle size of 0.5 μm or more and 2.0 μm or less,
- with a volume ratio in the range of coarse particle cBN powders:
- fine particle cBN powders=9.5 to 7:
- 0.5 to 3, provided that a total of the coarse particle cBN powders and the fine particle cBN powders is 10.
Dependencies are inferred from the claim text.