Heat treating of magnetic iron powder
First Claim
1. A process for the preparation of products having improved soft magnetic properties comprising the following stepsa) treating particles of an atomized or sponge iron powder with phosphoric acid at a temperature and for a time sufficient to form an insulating phosphorous containing layer material such that the phosphorus content is between 0.005 and 0.03% by weight of the atomized iron powder and between 0.02 and 0.06% by weight of the sponge iron powder,b) drying the obtained powder,c) optionally mixing the dry powder with a thermosetting resin,d) compacting the powder obtained from step b) or c) in a die, ande) heating the component obtained from step d) to a temperature between 350°
- -550°
C.
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Abstract
The invention concerns a method of compacting and heat-treating iron powders in order to obtain magnetic core components having improved soft magnetic properties. The iron powder consists of fine particles which are insulated by a thin layer having a low phosphorous content. According to the invention, the compacted iron powder is subjected to heat treatment at a temperature between 350° and 550° C.
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Citations
22 Claims
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1. A process for the preparation of products having improved soft magnetic properties comprising the following steps
a) treating particles of an atomized or sponge iron powder with phosphoric acid at a temperature and for a time sufficient to form an insulating phosphorous containing layer material such that the phosphorus content is between 0.005 and 0.03% by weight of the atomized iron powder and between 0.02 and 0.06% by weight of the sponge iron powder, b) drying the obtained powder, c) optionally mixing the dry powder with a thermosetting resin, d) compacting the powder obtained from step b) or c) in a die, and e) heating the component obtained from step d) to a temperature between 350°
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14. Iron powder for preparation of products having improved soft magnetic properties, the powder consisting essentially of particles of atomized or sponge iron powder having an insulating layer, the layer on the atomized iron powder comprising between 0.005 and 0.03% by weight of phosphorus and the layer on the sponge iron powder comprising between 0.02 and 0.06% by weight of phosphorus.
Specification