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AssigneeTDK Corporation
InventorsYukiharu Kinoshita, Hiroyasu Takahashi, Jun Sawai
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The present invention provides manganese-zinc-ferrite core fabrication process which can fabricate a manganese-zinc-ferrite core having high surface electrical resistance and low magnetic core losses without recourse to the introduction of nitrogen gas from the outside yet within a short time period, and such a manganese-zinc-ferrite core. To achieve this, manganese-zinc-ferrite core is formed into a given core shape. The core compact is fired in a firing atmosphere having an oxygen concentration controlled with carbonic acid gas and steam. Then, the compact is rapidly cooled at a cooling rate of 350° C./hour to 850° C./hour. In this way, a manganese-zinc-ferrite core is obtained.
A process of fabricating a manganese-zinc-ferrite core, which comprises forming manganese-zinc-ferrite into a given core shape, firing a core compact in a firing atmosphere having an oxygen concentration controlled by carbon dioxide and steam, and cooling said core compact at a cooling rate of about 50° C./hour to 850° C./hour, wherein said manganese-zinc-ferrite contains calcium oxide as a subordinate component in an amount of 0.04% by weight to 0.6% by weight as calculated on a CaO basis;
Dependencies are inferred from the claim text.