Other

H&ouml;gan&auml;s Ab

Lars-&angst;ke Larsson

Anne Larsson-Westberg

Cecilia Elgelid

Patricia Jansson

The invention concerns a process for the preparation of an insulated soft magnetic powder comprising the steps of mixing particles of a soft magnetic iron base powder with an acidic, aqueous insulating-layer forming solution, in which MgO has been dissolved; and drying the obtained mixture to obtain an electrically insulating Mg containing layer on the particle surfaces. The invention also concerns the powder per se as well as compressed soft magnetic powder cores prepared from the powder.

Iron powder and method for the preparation thereof

The invention concerns a process for the preparation of a compressed soft magnetic powder core comprising the steps of compacting an iron based powder the particles of which are insulated by a chromium containing layer, at a pressure between 300 and 1500 Mpa. The compacted body is then heated to a temperature sufficient for achieving stress relief and recrystallization of the iron base material.

Compressed soft magnetic materials

The invention concerns a novel low oxygen powder comprising particles of a base powder consisting of essentially pure iron having an insulating oxygen- and phosphorus-containing barrier. The oxygen content of the new powder is at most 0.2% by weight higher than the oxygen content of the base powder, and the ratio O:P is between 30 and 1, preferably between 15 and 2 and most preferably between 10 and 3 as measured by the ESCA method. The invention also concerns a new method of preparing an iron-based powder comprising the steps of preparing a base powder consisting of a water atomized iron powder or a sponge iron powder, subjecting the mixture to treatment with a solution of phosphoric acid in an organic solvent and drying the obtained mixture, whereby the solution of phosphoric acid is sprayed on the base powder while being mixed.

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Höganäs, Sweden

Lars-&angst;ke Larsson