Cemented Carbide, Cutting Tool Containing the Same, and Method of Manufacturing Cemented Carbide
AssigneeSumitomo Electric Industries, Ltd.
InventorsMasato Michiuchi, Kosuke Fukae
Life of this patent
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Abstract
Cemented carbide contains first hard-phase particles containing WC, second hard-phase particles which contain carbonitride containing at least Ti and Nb, and a metallic binder phase containing an iron-group element. The second hard-phase particle includes a granular core portion and a peripheral portion which covers at least a part of the core portion. The core portion contains composite carbonitride expressed as Ti1-X-YNbXWYC1-ZNZ, where Y is not smaller than 0 and not greater than 0.05 and Z is not smaller than 0.3 and not greater than 0.6. The peripheral portion is different in composition from the core portion.
Claims11
Cemented carbide comprising:
- first hard-phase particles containing WC;
- second hard-phase particles which contain carbonitride containing at least Ti and Nb;
- and
- a metallic binder phase containing an iron-group element,
- the second hard-phase particle including a granular core portion and a peripheral portion which covers at least a part of the core portion,
- the core portion containing composite carbonitride expressed as Ti1-X-YNbXWYC1-ZNZ, where Y is not smaller than 0 and not greater than 0.05 and Z is not smaller than 0.3 and not greater than 0.6, and
- the peripheral portion being different in composition from the core portion.
A method of manufacturing cemented carbide comprising:
- a first step of obtaining powders of composite carbonitride expressed as Ti1-X-YNbXWYC1-ZNZ;
- a second step of obtaining mixed powders by mixing the powders of the composite carbonitride, WC powders, and powders of an iron-group element;
- a third step of obtaining a formed material by pressing the mixed powders;
- and
- a fourth step of obtaining a sintered material by sintering the formed material,
- Y being not smaller than 0 and not greater than 0.05,
- Z being not smaller than 0.3 and not greater than 0.6,
- the first step including
- a first operation of obtaining third powders by mixing first powders containing two elements of Ti and Nb or three elements of Ti, Nb, and W and second powders containing at least graphite,
- a second operation of obtaining a granulated material by granulating the third powders,
- a third operation of obtaining a powder precursor composed of the composite carbonitride by subjecting the granulated material to heat treatment at a temperature not lower than 1800° C. in an atmosphere containing nitrogen gas, and
- a fourth operation of obtaining the powders of the composite carbonitride by breaking the powder precursor.
Dependencies are inferred from the claim text.