Pressing oriented pellets in a magnetic field

Patent metadata

Field	Value
Publication number	US-11325335-B2
Application number	US-201916534283-A
Country	US
Kind code	B2
Filing date	Aug 7, 2019
Priority date	Aug 7, 2018
Publication date	May 10, 2022
Grant date	May 10, 2022

Abstract

Disclosed herein is a method and apparatus for forming pellets in a non-ambient environment such as a strong magnetic field. The apparatus includes a die body, a die bottom, a short push pin, a long push pin, a press tube, and an extended push pin. A powder is loaded into the die body, which is then positioned in the non-ambient environment, and the powder allowed to equilibrate. A pellet is then formed by pressing on the extended push pin while the powder is in the non-ambient environment.

First claim

What is claimed is:

1. A method comprising:
providing an apparatus comprising:
a die body having a first cylindrical hole therethrough;
a die bottom attached to the die body to cover a first opening of the first hole;
a cylindrical short push pin shorter than the first hole and having the same cross-section as the first hole inserted into the first hole;
a long push pin having a first cylindrical end having the same cross-section as the first hole and a second end having a smaller cross-section than the first end;
an O-ring around the second end;
a press tube having a second hole therethrough attachable to the die body to align the second hole with a second opening of the first hole; and
an extended push pin that fits through the second hole;
wherein the combined length of the short push pin, the long push pin, and the extended push pin is longer than the combined length of the first hole and the second hole;

placing a material into the first hole;
placing the first end of the long push pin into the first hole leaving a space between the material and the long push pin;
attaching the press tube to the die body;
placing the extended push pin in the second hole;
positioning the apparatus to place the material in a non-ambient environment;
allowing the material to at least partially equilibrate in the non-ambient environment; and
pressing on the extended push pin to form a pellet of the material while the material is in the non-ambient environment.

2. The method of claim 1 , wherein the non-ambient environment is a magnetic field.

3. The method of claim 2 , wherein the magnetic field is at least 1 T.

4. The method of claim 2 , wherein the material is barium hexaferrite.

5. The method of claim 2 , wherein the apparatus is non-magnetic.

6. The method of claim 1 , wherein the non-ambient environment is a magnetic field, a vacuum, an elevated temperature, an electric field, or any combination thereof.

7. The method of claim 1 , wherein the pressing on the extended push pin is outside of the non-ambient environment.

8. An apparatus comprising:
a die body having a first cylindrical hole therethrough;
a die bottom attached to the die body to cover a first opening of the first hole;
a cylindrical short push pin shorter than the first hole and having the same cross-section as the first hole inserted into the first hole;
a long push pin having a first cylindrical end having the same cross-section as the first hole inserted into the first hole and a second end having a smaller cross-section than the first end;
wherein the short push pin is between the die bottom and the first end of the long push pin;

an O-ring around the second end;
a press tube having a second hole therethrough attached to the die body to align the second hole with a second opening of the first hole; and
an extended push pin inserted into the second hole;
wherein the combined length of the short push pin, the long push pin, and the extended push pin is longer than the combined length of the first hole and the second hole.

9. The apparatus of claim 8 , wherein the apparatus is non-magnetic.

Assignees

• Us Gov Sec Navy
• The Government Of The Us Secretarv Of The Navy

Inventors

• Johnson Scooter David
• Xing Jeffrey Wang
• Doherty Michael

Classifications

• B30B15/304 Primary

  by using feed frames or shoes with relative movement with regard to the mould or moulds · CPC title

• B22F3/03

  Press-moulding apparatus therefor · CPC title

• H01F1/10

  non-metallic substances, e.g. ferrites {, e.g. [(Ba,Sr)O(Fe2O3)6] ferrites with hexagonal structure} · CPC title

• B22F3/004

  Filling molds with powder (feeding material to presses in general B30B15/302) · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title