Sintered ferrite material, wire wound component, and producing method of sintered ferrite material
AssigneeHitachi Metals, Ltd.
InventorsTomoyuki Tada, Yasuharu Miyoshi
Life of this patent
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Abstract
A sintered ferrite material, which is obtained by adding Bi2O3 in a range from 0.5% by mass to 3% by mass against 100% by mass of a material having a composition formula of (1-x-y-z)(Li0.5Fe0.5)O.xZnO.yFe2O3.zCuO wherein x, y and z satisfy 0.14≦x≦0.19, 0.48≦y<0.5 and 0≦z≦0.03 and satisfies resistivity equal to or higher than 106 Ωm, initial permeability equal to or higher than 200 and saturation magnetic flux density equal to or higher than 430 mT at 23° C. and equal to or higher than 380 mT at 100° C.
Claims13
A sintered ferrite material, which is obtained by adding Bi2O3 in a range from 0.5% by mass to 1.25% by mass against 100% by mass of a material having a composition formula of (1-x-y-z)(Li0.5Fe0.5)O.xZnO.yFe2O3.zCuO wherein x, y and z satisfy 0.14≦x≦0.19, 0.48≦y<0.5 and 0<z≦0.03, in which an average crystal grain size is in a range from 7.5 μm to 25 μm, and which satisfies initial permeability equal to or higher than 200, saturation magnetic flux density equal to or higher than 440 mT at 23° C. and equal to or higher than 380 mT at 100° C., and resistivity equal to or higher than 106 Ωm.
A producing method of a sintered ferrite material, comprising:
- a step of preparing raw powder to obtain a material having a composition formula of (1-x-y-z)(Li0.5Fe0.5)O.xZnO.yFe2O3.zCuO wherein x, y and z satisfy 0.14≦x≦0.19, 0.48≦y<0.5 and 0<z≦0.03;
- a step of pre-sintering the raw powder to obtain first pre-sintered powder;
- a step of adding Bi2O3 in a range from 0.5% by mass to 1.25% by mass against 100% by mass of the first pre-sintered powder to obtain second pre-sintered powder;
- a step of pulverizing the second pre-sintered powder to obtain pulverized powder;
- a step of forming the pulverized powder to obtain a compact;
- and
- a step of sintering the compact to obtain a sintered ferrite material in which an average crystal grain size is in a range from 7.5 μm to 25 μm.
A producing method of a sintered ferrite material, comprising:
- a step of preparing raw powder obtained by adding Bi2O3 to a starting (precursor) material used to obtain a ferrite composition formula of (1-x-y-z)(Li0.5Fe0.5)O.xZnO.yFe2O3.zCuO, wherein x, y and z satisfy 0.14≦x≦0.19, 0.48≦y<0.5 and 0<z≦0.03, wherein said Bi2O3 is added in a range from 0.5% by mass to 1.25% by mass against 100% by mass of said ferrite material;
- a step of pre-sintering the raw powder to obtain pre-sintered powder;
- a step of pulverizing the pre-sintered powder to obtain pulverized powder;
- a step of forming the pulverized powder to obtain a compact;
- and
- a step of sintering the compact to obtain a sintered ferrite material in which an average crystal grain size is in a range from 7.5 μm to 25 μm.
Dependencies are inferred from the claim text.