Composite powder filling method and composite powder filling device, and composite powder molding method and composite powder molding device

1. A process for filling a multi-powder, comprising the steps of:

moving a powder box, being disposed movably on a table and comprising a plurality of powder chambers, said powder chambers separated by partition plates on the inside of said powder box, storing a plurality of powders whose constituent compositions differ in a divided manner and having a bottom opening, onto a compacting die capable of forming a cavity into which the powders are filled; and

filling a plurality of the powders into the cavity at once through the bottom openings by introducing a gas into the powder chambers to substantially equalize the respective flow resistances of a plurality of the powders, at least when the bottom openings are positioned above the cavity by the powder box moving step,

wherein a gas flow Vg (mL/s) to be introduced into said powder chambers is such that an aeration value Vg/Vp, a ratio with respect to the volume Vp (mL) of the powders in the powder chambers, is from 0.1 to 0.3 (1/s) in each of said powder chambers,

wherein said gas is introduced through an introducing hole disposed on the outer peripheral side of a gas feed pipe for feeding the gas into each of said powder chambers, and said gas feed pipe is disposed on the bottom side each of said powder chambers;

wherein said aeration value is set per each of said powder chambers; and

wherein each of said powder chambers comprises a flow-resistance measuring device, wherein the flow resistance of said gas is measured independently in each of said powder chambers.

2. The process for filling a multi-powder set forth in claim 1 , wherein said powders are ferrous powders whose major component is iron and average particle diameter is 250 μm or less.

3. A process for compacting a multi-powder, comprising the steps of:

moving a powder box, being disposed movably on a table and comprising a plurality of powder chambers, said powder chambers separated by partition plates on the inside of said powder box, storing a plurality of powders whose constituent compositions differ in a divided manner and having a bottom opening, onto a compacting die forming a cavity into which the powders are filled;

filling a plurality of the powders into the cavity at once through the bottom openings by introducing a gas into the powder chambers to substantially equalize the respective flow resistances of a plurality of the powders, at least when the bottom openings are positioned above the cavity by the powder box moving step; and

producing a multi-powder compact by pressurizing a multi-powder comprising a plurality of the powders after the filling step,

wherein a gas flow Vg (mL/s) to be introduced into said powder chambers is such that an aeration value Vg/Vp, a ratio with respect to the volume Vp (mL) of the powders in the powder chambers, is from 0.1 to 0.3 (1/s) in each of said powder chambers,

wherein said gas is introduced through an introducing hole disposed on the outer peripheral side of a gas feed pipe for feeding the gas into each of said powder chambers, and a gas feed pipe for each of said chambers is disposed on the bottom side each of said powder chambers;

wherein said aeration value is set per each of said powder chambers; and

wherein each of said powder chambers comprises a flow-resistance measuring device, wherein the flow resistance of said gas is measured independently in each of said powder chambers.

4. The process for filling a multi-powder set forth in claim 1 , wherein said aeration value set is set to 0.15 (1/s).

5. The process for filling a multi-powder set forth in claim 1 , wherein said gas is dry air or an inert gas, which does not oxidize said powders.

6. The process for filling a multi-powder set forth in claim 1 , wherein said gas or said powders are heated.

7. The process for filling a multi-powder set forth in claim 1 , wherein a gas supply source of said gas is a 0.4 MPA compressed air source.

8. The process for filling a multi-powder set forth in claim 7 , wherein independent air compressors are adapted for said gas supply source.

9. The process for filling a multi-powder set forth in claim 7 , wherein nitrogen gas cylinders are adapted for said gas supply source.

10. The process for filling a multi-powder set forth in claim 1 , wherein each of said flow resistance measuring devices comprise a load, which comprises a probe with a strain gage.

11. The process for filling a multi-powder set forth in claim 8 , wherein the flow resistances are controlled continuously or at predetermined intervals.

12. The process for filling a multi-powder set forth in claim 1 , wherein said powders are subjected to a segregation prevention treatment.