Method for fabricating a functionally-graded monolithic sintered working component for magnetic heat exchange and an article for magnetic heat exchange

Patent metadata

Field	Value
Publication number	US-10847289-B2
Application number	US-201815961110-A
Country	US
Kind code	B2
Filing date	Apr 24, 2018
Priority date	Aug 18, 2010
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

An article for magnetic heat exchange includes a functionally-graded monolithic sintered working component including La1-aRa(Fe1-x-yTyMx)13HzCb with a NaZn13-type structure. M is one or more of the elements from the group consisting of Si and Al, T is one or more of the elements from the group consisting of Mn, Co, Ni, Ti, V and Cr and R is one or more of the elements from the group consisting of Ce, Nd, Y and Pr. A content of the one or more elements T and R, if present, a C content, if present, and a content of M varies in a working direction of the working component and provides a functionally-graded Curie temperature. The functionally-graded Curie temperature monotonically decreases or monotonically increases in the working direction of the working component.

First claim

The invention claimed is:

1. An article for magnetic heat exchange, comprising:
a monolithic sintered working component comprising La 1-a R a (Fe 1-x-y T y M x ) 13 H z C b with a NaZn 13 structure, wherein M is one or more element selected from the group consisting of Si and Al, T is one or more element selected from the group consisting of Mn, Co, Ni, Ti, V and Cr, R is one or more element selected from the group consisting of Ce, Nd, Y, and Pr, 0≤a≤0.5, 0≤b≤1.5, 0.05≤x≤0.2, 0≤y≤0.2, and 0≤z≤3,
a content of at least one of the elements selected from the group consisting of T, R, C, and M varying in a working direction of the working component,
a Curie temperature monotonically decreasing or monotonically increasing in the working direction of the working component, and
the working component comprising an average gradient of the Curie temperature of 5° C./mm to 0.5° C./mm over 80% of a length of the working component.

2. The article according to claim 1 , wherein the Curie temperature increases or decreases with a gradient that lies within ±50% of a linear function over 80% of a length of the working component, and the linear function is defined as the difference between the Curie temperature in degrees Celsius at one end of the working component and the Curie temperature at an opposing end of the working component divided by a distance in millimeters between the two ends.

3. The article according to claim 2 , wherein the Curie temperature decreases or increases with a gradient that lies within ±5% of the linear function.

4. The article according to claim 2 , wherein the Curie temperature decreases or increases with a gradient that lies within ±10% of the linear function over 90% of the length of the working component.

5. The article according to claim 1 , wherein the working component has a density d in a defined portion of 5 vol % to 10 vol % of a total volume of the working component and wherein the density d lies within a range of ±5% of an average total density d av of the working component.

6. The article according to claim 1 , wherein the working component comprises an increasing M content in the working direction of the working component or a decreasing M content in the working direction of the working component for increasing amounts of one or more of the elements T and R in the working direction of the working component.

7. The article according to claim 1 , wherein T of the working component comprises Co and/or Mn, M comprises Si, and a Si content, Si act , lying within ±5% of Si m , wherein Si m =3.85−0.0573×Co m −0.045×Mn m 2 +0.2965×Mn m , wherein Si m is a metallic weight fraction of Si, Mn m is a metallic weight fraction of Mn, and Co m is a metallic weight fraction of Co.

8. The article according to claim 1 , wherein nowhere along a length of the working component is there a gradient of the Curie temperature that exceeds 10° C./0.5 mm of the length.

9. An article for magnetic heat exchange, comprising:
a monolithic sintered working component comprising La 1-a R a (Fe 1-x-y T y M x ) 13 H z C b with a NaZn 13 structure, wherein M is one or more element selected from the group consisting of Si and Al, T is one or more element selected from the group consisting of Mn, Co, Ni, Ti, V and Cr, R is one or more element selected from the group consisting of Ce, Nd, Y, and Pr, 0≤a≤0.5, 0≤b≤1.5, 0.05≤x≤0.2, 0≤y≤0.2, and 0≤z≤3,
a content of at least one of the elements selected from the group consisting of T, R, C, and M varying in a working direction of the working component, and
a Curie temperature monotonically decreasing or monotonically increasing in the working direction of the working component, wherein nowhere along a length of the working component is there a gradient of the Curie temperature that exceeds 10° C./0.5 mm of the length.

10. The article according to claim 9 , wherein the Curie temperature increases or decreases with a gradient that lies within ±50% of a linear function over 80% of a length of the working component, and the linear function is defined as the difference between the Curie temperature in degrees Celsius at one end of the working component and the Curie temperature at an opposing end of the working component divided by a distance in millimeters between the two ends.

11. The article according to claim 10 , wherein the Curie temperature decreases or increases with a gradient that lies within ±5% of the linear function.

12. The article according to claim 10 , wherein the Curie temperature decreases or increases with a gradient that lies within ±10% of the linear function over 90% of the length of the working component.

13. The article according to claim 9 , wherein the working component has a density d in a defined portion of 5 vol % to 10 vol % of a total volume of the working component and wherein the density d lies within a range of ±5% of an average total density day of the working component.

14. The article according to claim 9 , wherein the working component comprises an increasing M content in the working direction of the working component or a decreasing M content in the working direction of the working component for increasing amounts of one or more of the elements T and R in the working direction of the working component.

15. The article according to claim 9 , wherein T of the working component comprises Co and/or Mn, M comprises Si, and a Si content, Si act , lying within ±5% of Si m , wherein Si m =3.85−0.0573×Co m −0.045×Mn m 2 +0.2965×Mn m , wherein Si m is a metallic weight fraction of Si, Mn m is a metallic weight fraction of Mn, and Co m is a metallic weight fraction of Co.

16. The article according to claim 15 , wherein Si act lies within ±2% of Si m .

17. The article according to claim 9 , wherein 0.05≤b≤0.5.

18. The article according to claim 9 , wherein 1.4<z≤3.

19. The article according to claim 9 , wherein T is selected from one or more of the group consisting of Co and Ni and wherein z=0.

20. The article according to claim 9 , wherein T is selected from one or more of a group consisting of Mn, Ti, V and Cr, R is selected from one or more of a group consisting of Ce, Nd and Pr, and wherein 1.4<z≤3.

Assignees

• Vacuumschmelze Gmbh & Co Kg

Inventors

• Katter Matthias
• Barcza Alexander
• Zellmann Volker

Classifications

• H01F1/01 Primary

  of inorganic materials (H01F1/44 takes precedence) · CPC title

• H01F1/015 Primary

  Metals or alloys · CPC title

• Y10T428/24992

  Density or compression of components · CPC title

• H01F1/017 Primary

  Compounds · CPC title

• Y10T29/4935

  Heat exchanger or boiler making · CPC title