Patent US5350628A successfully refreshed from Google Patents.
US5350628A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic sintered composite material
Assignee: Panasonic Holdings Corp
•
Filing: 1992-11-19
•
Granted: 1994-09-27
•
Expires: 2012-11-19
Abstract
Abstract A magnetic material is provided which includes a discrete phase including grains made of a first substance which comprises a magnetic metal; and a continuous phase including a thin coating film made of a second substance which comprises a dielectric or insulating substance. The thin coating film is formed on the surface of the grains and has a mean thickness smaller than the mean particle size of the grains. The grains are separated substantially from each other by the thin coating film.
Inventors
- 👤 Koichi Kugimiya
- 👤 Yasuhiro Sugaya
- 👤 Osamu Inoue
- 👤 Ken Hirota
- 👤 Mitsuo Satomi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 06:31
CPC Classifications
H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/09; G; G11; G11B; G11B5/00; G11B5/127; G11B5/133; G11B5/187; G11B5/193; H01F1/04; H01F1/06; H01F1/08; H01F1/083; H01F1/12; H01F1/14; H01F1/20; H01F1/22; H01F1/24; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/11; Y10T428/115; Y10T428/249921; Y10T428/249953; Y10T428/249955; Y10T428/249956; Y10T428/29; Y10T428/2982; Y10T428/2991
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
135 words
A magnetic sintered composite material comprising: a discrete phase including grains made of a first substance which comprises a magnetic metal or alloy thereof; and a continuous phase consisting essentially of a dielectric thin coating film of an oxide or nitride of a metal or alloy, said thin coating film being formed on the surface of said grains and having a mean thickness smaller than the mean particle size of said grains, wherein said grains are separated substantially from each other by said thin coating film, said magnetic sintered composite material having an electrical resistivity on the order of at least 10 6 times that of said magnetic metal or alloy thereof, said first substance being an alloy selected from the group consisting of an iron-aluminum, an iron-silicon, an iron-nickel, an iron-nickel-molybdenum, and an iron-silicon-aluminum-cobalt.
Claim 2
Dependent Claim
135 words
A magnetic sintered composite material comprising: a discrete phase including grains made of a first substance which comprises a magnetic metal or alloy thereof; and a continuous phase consisting essentially of a dielectric thin coating film of an oxide or nitride of a metal or alloy, said thin coating film being formed on the surface of said grains and having a mean thickness smaller than the mean particle size of said grains, wherein said grains are separated substantially from each other by said thin coating film, said magnetic sintered composite material having an electrical resistivity on the order of at least 10 6 times that of said magnetic metal or alloy thereof, said first substance being an alloy selected from the group consisting of an iron-aluminum, an iron-silicon, an iron-nickel, an iron-nickel-molybdenum, and an iron-silicon-aluminum-cobalt.
Claim 3
Dependent Claim
67 words
A magnetic sintered composite material according to claim 1, wherein said first substance contains an alloy selected from the group consisting of an iron-aluminum, an iron-silicon, an iron-nickel, an iron-nickel-molybdenum, and an iron-silicon-aluminum-cobalt, said grains made of the first substance have a mean particle size ensuring the formation of a single magnetic domain structure, and the axes of easy magnetization of said grains coincide with each other.
Claim 4
Dependent Claim
35 words
A magnetic sintered composite material according to claim 1, wherein said thin coating film is formed from a member of the group consisting of aluminum oxide, aluminum nitride, magnesium oxide, manganese-zinc ferrites and nickel-zinc ferrites.
Claim 5
Dependent Claim
16 words
A magnetic sintered composite material according to claim 1, having a porosity of 5% or less.
Claim 6
Dependent Claim
16 words
A magnetic sintered composite material according to claim 4, having a porosity of 0.5% or less.
Claim 7
Dependent Claim
21 words
A magnetic sintered composite material according to claim 1, wherein said grains made of the first substance have a platelet shape.
Claim 8
Dependent Claim
21 words
A magnetic sintered composite material according to claim 1, wherein said grains made of the first substance have a needlelike shape.
Claim 9
Dependent Claim
16 words
A magnetic sintered composite material according to claim 6, having a porosity of 0.1% or less.
Claim 10
Dependent Claim
23 words
A magnetic sintered composite material according to claim 6, having a microstructure in which said grains made of the first substance are oriented.
Claim 11
Dependent Claim
23 words
A magnetic sintered composite material according to claim 6, wherein said platelet grains have an axis of easy magnetization along their major axes.
Claim 12
Dependent Claim
39 words
A magnetic head comprising a magnetic core which is made of a magnetic sintered composite material of claim 6, wherein said grains oriented in the magnetic core have their flat surface perpendicular to a running direction of magnetic media.
Claim 13
Dependent Claim
21 words
A magnetic head according to claim 11, wherein said platelet grains have an axis of easy magnetization along their major axes.
Claim 14
Dependent Claim
19 words
A magnetic sintered composite material according to claim 1, wherein said magnetic material is formed as a magnetic head.
Claim 15
Dependent Claim
22 words
A magnetic sintered composite material according to claim 1, wherein said magnetic material is formed as a core of a magnetic transformer.
Claim 16
Dependent Claim
19 words
A magnetic sintered composite material according to claim 1, wherein said magnetic material is formed as a hard magnet.
References Cited (Backward Citations)
US3255052A
Cited
US4101348A
Cited
US3739445A
Cited
US3814598A
Cited
US3933536A
Cited
US3892600A
Cited
US3948690A
Cited
US4133677A
Cited
US4177089A
Cited
US4518674A
Cited
US4337087A
Cited
JPS55156029A
Cited
US4431604A
Cited
US4323395A
Cited
US4414271A
Cited
US4496626A
Cited
EP0088992A2
Cited
US4543208A
Cited
JPS59182972A
Cited
US4601753A
Cited
JPS60152656A
Cited
EP0158338A2
Cited
JPS60261031A
Cited
DE3603061A1
Cited
US5238507A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-09-26 | 1998-03-28 | 1998-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-09-26 | 2002-03-28 | 2002-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-09-26 | 2006-03-28 | 2006-09-27 | $7700.00 | Window Closed / Lapsed |