Composite permanent magnet for magnetic excitation and method of producing the same
AssigneeHitachi Metals, Ltd.
InventorMuneyoshi Eino
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Abstract
The present invention relates to a composite permanent magnet for magnetic excitation, used in a permanent type rotary machine such as permanent magnet type generators or permanent magnet type motors, which composite magnet comprises a first part and a second part both of which have the same basic composition, the first part having a higher residual magnetic flux density Br than the other, the second part having a higher coercive force .sub.I H.sub.c than the first part, the first and second parts being integrated into one body. The composite permanent magnet has superior characteristics as composite permanent magnet for magnetic excitation.
Claims6
A method of producing a composite permanent magnet for magnetic excitation comprising a first material and a second material both of which have the same basic composition integrally formed into one body, said first material having a higher residual magnetic flux density Br as compared to the second material, and said second material having a higher coercive force .sub.I Hc as compared to the first material wherein oxide powder mainly containing Mo.nFe.sub.2 O.sub.3 (where M is an element selected from the group consisting of Ba, Sr, Pb and Ca or a mixture thereof, and n is a number of 5 to 6) is compacted, then a part of the resultant compacted body is impregnated with a liquid containing one kind or more cations or electropositive atoms of metallic or semimetallic elements, or one or more molecular cations or electropositive molecules containing one or more metallic or semimetallic elements, or a mixture thereof, and the body being fired so that the coercive force .sub.I HC of the part impregnated with said liquid become higher than that of the non-impregnated part because of a substance contained in said liquid.
Dependencies are inferred from the claim text.