Abstract: A regenerator for a magnetic heat exchanger is provided. The regenerator comprises a housing having a chamber, an inlet and outlet for a working medium, and a chamber volume V. At least one magnetocalorically active component is arranged in the chamber between the inlet and the outlet and has at least one inner flow channel with a hydraulic diameter dhyd. The volume of the chamber not occupied by the magnetocalorically active component provides at least one bypass flow channel, both the inlet and the outlet being reached from the at least one bypass flow channel, and this bypass flow channel having a hydraulic diameter D, where D>dhyd. The at least one inner flow channel of the magnetocalorically active component is in flow communication with the bypass flow channel. The magnetocalorically active component and the at least one bypass flow channel are arranged parallel to one another.

Abstract: In an embodiment, a method of fabricating a working component for magnetic heat exchange comprises arranging at least two articles comprising a magnetocalorically active phase and an elongated form with a long axis having a length 1 and a shortest axis having a length s, wherein 1?1.5 s, such that the shortest axes of the at least two articles are substantially parallel to one another and securing the at least two articles in a position within the working component such that the shortest axes of the at least two articles are substantially parallel to one another within the working component.

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.

Abstract: In an embodiment, a method of fabricating a working component for magnetic heat exchange comprises arranging at least two articles comprising a magnetocalorically active phase and an elongated form with a long axis having a length 1 and a shortest axis having a length s, wherein 1?1.5 s, such that the shortest axes of the at least two articles are substantially parallel to one another and securing the at least two articles in a position within the working component such that the shortest axes of the at least two articles are substantially parallel to one another within the working component.

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.

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.

Abstract: A process of fabricating a monolithic working component for magnetic heat exchange is disclosed. The process includes mixing two or more portions comprising amounts of La, Fe, Si and at least one of T and R suitable to produce a La1-aRa(Fe1-x-yTySix)13Hz phase, wherein T is at least one element from the group consisting of Mn, Co, Ni and Cr and R is at least one element from the group consisting of Ce, Nd, Y and Pr. The amount of T, R, and Si is selected for each of the two or more portions to provide the two or more portions with differing Curie temperatures and, preferably, a density, d, within a range of ±5% of an average density, dav, of a total number of portions. The process includes heat treating a single monolithic green body formed from two or more precursor powder mixtures to produce a single monolithic working component.

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.

Abstract: An article for magnetic heat exchange comprises a monolithic working component comprising two or more portions. The two or more portions comprise amounts of La, Fe, Si and of one or more elements T and R suitable to produce a La1-aRa(Fe1-x-yTySix)13Hz phase, wherein T is one or more of the elements from the group consisting of Mn, Co, Ni and Cr and R is one or more of the elements from the group consisting of Ce, Nd, Y and Pr. The amount of the one or more elements T and R and the amount of Si is selected for each of the two or more portions to provide the two or more portions with differing Curie temperatures and, preferably, a density, d, within a range of ±5% of an average density, dav, of a total number of portions.

Abstract: A working component for magnetic heat exchange comprises a magnetocalorically active phase comprising La1-aRa(Fe1-x-yTyMx)13Hz, a hydrogen content, z, 90% or higher of a hydrogen saturation value, zsat, and values of a, x and y selected to give a Curie temperature Tc. M is one or more of the elements from the group consisting of Al and Si, T is one or more of the elements from the group consisting of Co, Ni, Mn, Cr, Cu, Ti and V and R is one or more of the elements from the group consisting of Ce, Nd, Y and Pr. Tcmax is a Curie temperature of a La1-aRa(Fe1-x-yTyMx)13Hz phase comprising a hydrogen content z=zsat and said selected values of a, x and y. The working component comprises the Tc wherein (Tcmax?Tc)?20K.