Patent ID: 11946119
Assignee: JFE STEEL CORPORATION
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  B  Y | IPC B  C

Claim 0:
1. A powder mixture for powder metallurgy, comprising:
a raw material powder;
a copper powder;
a binder;
a graphite powder; and
carbon black,
wherein the binder is one or more resins selected from the group consisting of copolyamide and polyurethane,
the raw material powder contains an iron-based powder in an amount of 90 mass % or more with respect to the raw material powder,
an average particle size of the graphite powder is less than 5 μm,
a ratio [mb/(mr+mg+mCu+mc)×100] of a mass mb of the binder to a sum of a mass mr of the raw material powder, a mass mg of the graphite powder, a mass mCu of the copper powder, and a mass mc of the carbon black is 0.3 mass % to 0.80 mass %,
a ratio [mg/(mr+mg+mCu+mc)×100] of the mass mg of the graphite powder to the sum of the mass mr of the raw material powder, the mass mg of the graphite powder, the mass mCu of the copper powder, and the mass mc of the carbon black is 0.6 mass % to 1.0 mass %,
a ratio [mCu/(mr+mg+mCu+mc)×100] of the mass mCu of the copper powder to the sum of the mass mr of the raw material powder, the mass mg of the graphite powder, the mass mCu of the copper powder, and the mass mc of the carbon black is 0.1 mass % to 3.0 mass %,
a ratio [mc/(m, +mg+mCu+mc)×100] of the mass mc of the carbon black to the sum of the mass mr of the raw material powder, the mass mg of the graphite powder, the mass mCu of the copper powder, and the mass mc of the carbon black is 0.01 mass % to 0.30 mass %,
a surface of the raw material powder is coated with at least part of the binder, and
a surface of the binder is coated with at least part of the graphite powder, at least part of the copper powder, and at least part of the carbon black.