Article made of a granular magnetocalorically active material for heat exchange
View Patent ↗Article for magnetic heat exchange having a mantle enveloping at least one core, wherein the core comprises a plurality of grains having a magnetocalorically active material.
1. An article comprising:
at least one core, comprising a plurality of reactively sintered grains comprising a magnetocalorically active material; and
a mantle enveloping said at least one core.
2. The article according to claim 1 , wherein the magnetocalorically active material has a Curie temperature in the range of 220K to 345K.
3. The article according to claim 1 , wherein the magnetocalorically active material is one of Gd, a La(Fe.sub 1-b sub b ) 13 -based phase, a Gd 5 (Si, Ge) 4 -based phase, a Mn(As, Sb)-based phase, a MnFe(P, As)-based phase, a Tb—Gd-based phase, a (Pr, Nd, Sr) MnO 3 -based phase or a Pr e (Fe, Co) 17 -based phase.
4. The article according to claim 1 , wherein adjacent grains of the plurality of grains are contiguous.
5. The article according to claim 1 , wherein said at least one core comprises a plurality of cores enveloped by the mantle.
6. The article according to claim 5 , further comprising a matrix in which the plurality of cores are embedded.
7. The article according to claim 6 , wherein the matrix and the mantle comprise the same materials.
8. The article according to claim 6 , wherein the matrix and the mantle comprise different materials.
9. The article according to claim 1 , where the mantle is plastically deformable.
10. The article according to claim 1 , where the mantle comprises two layers.
11. The article according to claim 1 , wherein the mantle comprises copper or a copper alloy or aluminium or an aluminium-based alloy.
12. The article according to claim 1 , wherein the article is elongate.
13. The article according to claim 12 , wherein the article is in the form of a tape or a wire or a plate.
14. An article comprising:
at least one core, comprising a plurality of reactively sintered grains comprising a magnetocalorically active material; and
a mantle enveloping said at least one core, wherein the article is in the form of a solenoid coil, or is in the form of one or more pancake coils.
15. The article according to claim 14 , wherein the article is wound in the form of a solenoid coil.
16. The article according to claim 14 , wherein the article is wound in the form of a pancake coil.
17. The article according to claim 16 , wherein the article further comprises a plurality of pancake wound coils.
18. The article according to claim 17 , wherein each coil comprises a magnetocalorically active material having a different T c .