Method for heat treating an object containing at least one rare-earth element with a high vapor pressure

Patent metadata

Field	Value
Publication number	US-12318843-B2
Application number	US-202418616562-A
Country	US
Kind code	B2
Filing date	Mar 26, 2024
Priority date	Mar 31, 2021
Publication date	Jun 3, 2025
Grant date	Jun 3, 2025

Abstract

A method is provided for the heat treatment of an object comprising at least one rare-earth element with a high vapor pressure. One or more objects comprising at least one rare-earth element with a high vapor pressure are arranged in an interior of a package. An external source of the at least one rare-earth element is arranged so as to compensate for the evaporation of this same rare-earth element from the object and/or to increase the vapor pressure of the rare-earth element in the interior of the package, and the package is heat treated.

First claim

What is claimed is:

1. A method for heat treating an object, the method comprising the following:
providing a package comprising a plate, a box having a base and walls that surround the base, and a cover, wherein the base has a hole and the box comprises iron foil and/or the plate comprises an iron plate;
placing a powder material onto the base of the box;
arranging the plate on the powder material on the base of the box;
arranging one or more objects on the plate, wherein the one or more objects include at least one of Sm, Dy, Er, Eu, and Yb;
arranging an external source of the at least one of Sm, Dy, Er, Eu, and Yb within the box, the external source being provided by an alloy of iron and the at least one of Sm, Dy, Er, Eu, and Yb;
placing the cover on the walls, thus forming an interior volume;
wherein the powder material provides a mechanical obstacle to gas exchange between the interior volume and an environment outside of the interior volume of the package; and
heat treating the package.

2. A method according to claim 1 , wherein the one or more objects comprises an SmCo alloy that is heat treated in order to produce a Sm 2 Co 17 - or Sm 1 Co 5 -type magnet.

3. A method according to claim 1 , wherein the package is subjected to heat treatment at a temperature above 1000° C.

4. A method according to claim 1 , wherein the external source comprises at least 0.04 wt % of the at least one of Sm, Dy, Er, Eu, and Yb, based on the total weight of the one or more objects.

5. A method according to claim 1 , wherein a layer of powder comprising the at least one of Sm, Dy, Er, Eu, and Yb is applied to an inside of the package.

6. A method according to claim 1 , wherein the external source comprises samarium hybrid.

7. A method according to claim 1 , wherein the alloy of iron and the at least one of Sm, Dy, Er, Eu, and Yb is formed on the surface of the iron foil and/or iron plate by heat treating the iron foil and/or the iron plate in an atmosphere containing the at least one of Sm, Dy, Er, Eu, and Yb.

8. A method according to claim 1 , wherein the package further comprises a support structure for the one or more objects, wherein the support structure is placed on the plate and the one or more objects are arranged in the support structure.

9. A method according to claim 8 , wherein the support structure comprises iron and the external source is provided on the surface of the support structure by an alloy of iron and the at least one of Sm, Dy, Er, Eu, and Yb that is formed by heat treating the support structure in an atmosphere containing the at least one of Sm, Dy, Er, Eu, and Yb.

10. A method according to claim 8 , wherein a layer of a powder comprising the at least one of Sm, Dy, Er, Eu, and Yb is applied to the support structure.

11. A method according to claim 1 , wherein the powder material is an additional external source of the at least one of Sm, Dy, Er, Eu, and Yb that is contained in the one or more objects.

12. A method according to claim 11 , wherein the powder material comprises a content of the at least one of Sm, Dy, Er, Eu, and Yb of at least 15 wt %.

13. A method according to claim 1 , wherein the powder material is made up of different powder materials.

14. A method according to claim 13 , wherein the powder material comprises the external source of the at least one of Sm, Dy, Er, Eu, and Yb and an active material.

15. A method according to claim 14 , wherein the powder material comprises a lower layer comprising the at least one of Sm, Dy, Er, Eu, and Yb, and an upper layer comprising an active material.

16. A method according to claim 15 , wherein the active material is an oxygen getter.

17. A method according to claim 1 , wherein the cover is fastened to the walls of the box in a gas-tight manner.

18. A method according to claim 1 , wherein the external source is formed on the plate and/or on the inside of the box and/or on the cover.

Assignees

• Vacuumschmelze Gmbh & Co Kg

Inventors

• Üstüner Kaan
• Katter Matthias
• Brombacher Christoph
• Benedikt Daniela

Classifications

• H01F41/0253

  for manufacturing permanent magnets · CPC title

• H01F1/055

  and magnetic transition metals, e.g. SmCo5 · CPC title

• C22C2202/02

  Magnetic · CPC title

• C22C19/07

  based on cobalt · CPC title

• B22F2301/155

  Rare Earth - Co or -Ni intermetallic alloys · CPC title