Vacuumschmelze Gmbh & Company Kg

Vacuumschemlze Gmbh

Volker Zellmann

Matthias Katter

Alexander Barcza

Georg Werner Reppel

Georg-Werner Reppel

An article for magnetic heat exchange includes a functionally-graded monolithic sintered working component including LaR(FeTM)HCwith a NaZn-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.

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

An article for magnetic heat exchange comprising a magnetocalorically active phase with a NaZn-type crystal structure is provided by hydrogenating a bulk precursor article. The bulk precursor article is heated from a temperature of less than 50&#xb0; C. to at least 300&#xb0; C. in an inert atmosphere and hydrogen gas only introduced when a temperature of at least 300&#xb0; C. is reached. The bulk precursor article is maintained in a hydrogen containing atmosphere at a temperature in the range 300&#xb0; C. to 700&#xb0; C. for a selected duration of time, and then cooled to a temperature of less than 50&#xb0; C.

Article for magnetic heat exchange and method of fabricating an article for magnetic heat exchange

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 LaR(FeTSi)Hphase, 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 &#xb1;5% of an average density, d, 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.

Method of fabricating a working component for magnetic heat exchange

A method for the production of pressed permanent magnets comprises the following steps: A mixture of at least one magnetic powder and a thermosetting binder is provided and pressed to produce a moulded body. In order to obtain a permanent and particularly reliable protection against oxidation and corrosion, the moulded body is impregnated with an acid and solvent mixture in an impregnating bath before the cure of the thermosetting binder, whereby the entire surface of the permanent magnet is coated with a reaction layer [FIG.

Non-ageing permanent magnet from an alloy powder and method for the production thereof

The invention relates to a method for producing rod-shaped permanent magnets according to which pressed parts () are produced that are then assembled to a rod-shaped green product. Said green product is subsequently sintered, whereby a rod-shaped single-piece permanent magnet () is produced.

Method for producing rod-shaped permanent magnets

According to the inventive method for producing a composite part ( ), a support body ( ) is produced from a powder with a ferrous alloy base using powder metallurgy. A magnet body ( ) which is based on an alloy that is rich in rare earths is applied to the support body ( ) and both are then sintered in a furnace ( ), whereby a solid joint is formed between the support body ( ) and the magnet body ( ).

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Linsengericht, Germany

Volker Zellmann