Tungsten carbide powder and production method therefor
AssigneeSumitomo Electric Industries, Ltd.
InventorsMasato MICHIUCHI, Takamasa ONOKI, Katsumi OKAMURA, Takayuki FUDO, Takehiko HAYASHI
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Abstract
A tungsten carbide powder contains tungsten carbide as a main component and chromium, in which, when mass concentrations of tungsten and chromium are measured at 100 or more analysis points randomly selected from a field of view of SEM observation of the tungsten carbide powder, a standard deviation σ of distribution of the ratio by percentage of the concentration of chromium to the total concentration of tungsten and chromium is 0.5 or less.
Claims4
A tungsten carbide powder comprising tungsten carbide as a main component and chromium,
- wherein, when mass concentrations of tungsten and chromium are measured at 100 or more analysis points randomly selected from a field of view of SEM observation of the tungsten carbide powder, a standard deviation σ of distribution of the ratio by percentage of the concentration of chromium to the total concentration of tungsten and chromium is 0.5 or less.
A method for producing a tungsten carbide powder comprising:
- a step of obtaining a mixed dry powder by mixing a tungsten oxide and a chromium-containing solution, followed by drying under stirring;
- a step of obtaining a calcined powder by calcining the dry powder in the air atmosphere;
- a step of obtaining a mixed powder by mixing the calcined powder and a carbon source powder;
- and
- a step of obtaining a tungsten carbide powder by reducing the mixed powder by heat treatment in a hydrogen gas-containing atmosphere and carburizing the mixed powder at a temperature of 1,000° C. or higher.
Dependencies are inferred from the claim text.