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US 4,225,344 AGranted
Process for producing sintered hard metals and an apparatus therefor
AssigneeSumitomo Electric Industries, Ltd.
InventorsNaoji Fujimori, Masaya Miyake, Takaharu Yamamoto, Akio Hara
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Abstract
This invention relates to a process for producing sintered hard metals which comprises sintering a compact for the sintered hard metals or sintering a formed body obtained from the compact through a presintering treatment and, if necessary, a machining treatment, a part or all of the heating steps and cooling steps being carried out in an atmospheres of hydrogen and an atmosphere of carbon monoxide.
Claims6
A process for controlling the carbon content of cemented carbides or cemented carbide alloys during sintering comprising:
- (a) heating a cemented carbide or cemented carbide alloy compact to a first temperature between 800.degree. and 1200.degree. C. in a flowing atmosphere consisting essentially of hydrogen at a pressure of 300 torr or less, said temperature being sufficient to cause deoxidation of the compact but below the temperature which results in appreciable decarburization by hydrogen;
- (b) removing said hydrogen atmosphere at said first temperature;
- and
- (c) continuing to heat the powder body from said first temperature to the sintering temperature of the compact in a flowing atmosphere consisting essentially of carbon monoxide gas at reduced pressure.
1 more element
Dependencies are inferred from the claim text.