Mixed powder for powder metallurgy and manufacturing method thereof
AssigneeKobe Steel, Ltd.
InventorHironori Suzuki
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Abstract
This mixed powder for powder metallurgy, the powder having excellent fluidity and minimal graphite powder scattering, can be obtained relatively conveniently by mixing fine graphite having an average grain diameter of 4 μm or less with an iron based powder. The process is performed without the addition of a binder and while shearing force is applied. It is preferable that the fine graphite have an average grain diameter of 2.4 μm or less and be wet-milled. A portion of the fine graphite is preferably added in place of at least one constituent selected from the group consisting of carbon black, fullerene, carbon compounds carbonized by baking, and graphite having an average grain diameter of 5 μm or more.
Claims19
A method for manufacturing a mixed powder for powder metallurgy, comprising:
- crushing graphite to a fine graphite with a mean particle size of 2.4 μm or less, and
- mixing the fine graphite with an iron based powder while applying a shear force,
- wherein the fine graphite is mixed with an iron based powder, without adding a binder,
- the fine graphite is mixed with the iron based powder while applying the shear force using a mixer equipped with stirring vanes moving in such a manner as to cut the mixed powder of the fine graphite and the iron based powder, and
- the mixed powder has a graphite scattering ratio of 20% or less.
A method for manufacturing a mixed powder for powder metallurgy, comprising:
- crushing graphite to a fine graphite with a mean particle size of 2.4 μm or less, and
- mixing the fine graphite with an iron based powder while applying a shear force,
- wherein the fine graphite is mixed with an iron based powder to form a mixed powder, without adding a binder;
- the fine graphite is mixed with the iron based powder while applying the shear force using a mixer equipped with stirring vanes moving in such a manner as to cut the mixed powder of the fine graphite and the iron based powder, and
- the mixed powder has a graphite scattering ratio of 17% or less and a flowability of from 24.0 to 28.9 sec/50 g.
Dependencies are inferred from the claim text.