Iron based soft magnetic power
AssigneeHöganäs AB
InventorsZhou Ye, Ola Andersson
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Abstract
The present invention concerns a high purity, annealed iron powder suitable for the preparation of soft magnetic composites. The powder is distinguished in that the content of inevitable impurities is less than 0.30% by weight, the oxygen content is less than 0.05% by weight, and the specific surface area as measured by the BET method is less than 60 m2/kg.
Claims22
A high purity, annealed iron powder suitable for the preparation of soft magnetic composites consisting of a base powder, the particles of which are irregularly shaped and surrounded by an electrically insulating coating wherein the content of inevitable impurities of the base powder is less than 0.30% by weight, the oxygen content of the base powder is less than 0.05% by weight, and the specific surface area of the base powder as measured by the BET method is less than 60 m2/kg.
Method of preparing a soft composite material comprising the steps of:
- a) providing a pure water atomised iron powder having a total content of impurities of less than 0.30% by weight, and a specific surface area as measured by the BET method less than 60 m2/kg;
- b) annealing the iron powder in a reducing atmosphere at a temperature and for a time period sufficient to reduce the oxygen content to a value below 0.05% by weight of the iron powder;
- c) providing an electrically insulating coating on the iron powder particles;
- d) optionally mixing the obtained powder with a lubricant and/or binder;
- e) compacting in the powder obtained according to step d) to a green body;
- and
- f) optionally heating the obtained green body.
Dependencies are inferred from the claim text.