Metal treatment – Stock – Magnetic
Reexamination Certificate
1999-09-02
2002-02-26
Sheehan, John (Department: 1742)
Metal treatment
Stock
Magnetic
C148S306000, C148S310000, C148S311000, C148S313000, C148S330000, C148S425000, C420S121000, C420S435000, C420S440000
Reexamination Certificate
active
06350323
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a high permeability metal glassy alloy for high frequencies which has high electric resistance and high magnetic permeability in a high frequency region.
2. Description of the Related Art
Some of multi-element alloys have the property that in quenching a composition in a melt state, the composition is not crystallized but is transferred to a glassy solid through a super cooled liquid state having a predetermined temperature width. This type of amorphous alloy is referred to as a “metal glassy alloy”. Examples of conventional known amorphous alloys include Fe—P—C system amorphous alloys first produced in the 1960s, (Fe, Co, Ni)—P—B system and (Fe, Co, Ni)—Si—B system amorphous alloys produced in the 1970s, (Fe, Co, Ni)—M(Zr, Hf, Nb) system amorphous alloys and (Fe, Co, Ni)—M(Zr, Hf, Nb)—B system amorphous alloys produced in the 1980s, and the like. Since these amorphous alloys have magnetism, they are expected to be used as amorphous magnetic materials as molding materials such as a core material of a transformer, and the like.
However, all of these amorphous alloys generally have a super cooled liquid region having a small temperature interval &Dgr;Tx, i.e., a small difference (Tx−Tg) between the crystallization (Tx) and the glass transition temperature (Tg), and must be thus produced by quenching at a cooling rate in the 10
5
° C./s (K/s) level by a melt quenching method such as a single roll method or the like. The product has the shape of a ribbon having a thickness of 50 &mgr;m or less, and a bulky amorphous solid cannot be obtained.
Examples of metal glassy alloys which have a super cooled liquid region having a relatively large temperature interval, and from which amorphous solids can be obtained by slowly cooling include Ln—Al—TM, Mg—Ln—TM, and Zr—Al—TM (wherein Ln represents a rare earth element, and TM represents a transition metal) system alloys produced in 1988 to 1991, and the like. Although amorphous solids having a thickness of several mm are obtained from these metal glassy alloys, these alloys have no magnetism and thus cannot be used as magnetic materials.
Examples of conventional known amorphous alloys having magnetism include Fe—Si—B system alloys. Such amorphous alloys have a high saturation flux density, but sufficient soft magnetic characteristics cannot be obtained. Also these amorphous alloys have low heat resistance, a low electric resistance, and low magnetic permeability in a frequency region of 1 kHZ or more, particularly in a high frequency region of 100 kHz or more, thereby causing the problem of a large eddy current loss in use as a core material for a transformer, or the like.
On the other hand, Co-based amorphous alloys such as Co—Fe—Ni—Mo—Si—B system amorphous alloys and the like have excellent soft magnetic properties. However, such amorphous alloys have poor thermal stability and insufficient electric resistance, thereby causing the practical problem of a large eddy current loss in use as a core material for a transformer, or the like.
Furthermore, amorphous materials can be formed from these Fe—Si—B system and Co-based amorphous alloys only under conditions in which a melt is quenched, as described above, and a bulky solid can be formed only by the steps of grinding a ribbon obtained by quenching a melt, and then sintering the powder under pressure. There are the problems of a large number of required steps, and the brittleness of the molded product.
SUMMARY OF THE INVENTION
Accordingly, it is a first object of the present invention to provide a high permeability metal glassy alloy for high frequencies, which has a large temperature interval of a super cooled liquid region, which exhibits soft magnetism at room temperature, and which has the possibility that it can be produced in a thicker shape than amorphous alloy ribbons obtained by a conventional melt cooling method, as well as low magnetostriction, high electric resistance, and high magnetic permeability in a high frequency region.
A second object of the present invention is to provide a high permeability metal glassy alloy for high frequencies comprising at least one element of Fe, Co, and Ni as a main component, at least one element of Zr, Nb, Ta, Hf, Mo, Ti, V, Cr and W, and B, wherein the super cooled liquid region has a temperature interval &Dgr;Tx of 20° C. (K) or more, which is represented by the equation &Dgr;Tx=Tx−Tg (wherein Tx represents the crystallization temperature, and Tg represents the glass transition temperature), and the electric resistance is 200 &mgr;&OHgr;·cm or more.
The above-described high permeability metal glassy alloy for high frequencies is represented by the following composition formula:
T
100−x−y
M
x
B
y
wherein T is at least one element of Fe, Co and Ni, M is at least one element of Zr, Nb, Ta, Hf, Mo, Ti, V, Cr and W, 4 atomic %≦x≦15 atomic %, and 22 atomic %≦y≦33 atomic %.
The high permeability glassy alloy for high frequencies having the above construction preferably has &Dgr;Tx of 50° C. (K) or more, and satisfies the relations 5 atomic %≦x≦12 atomic %, and 22 atomic %≦y≦33 atomic % in the composition formula T
100−x−y
M
x
B
y
.
The high permeability glassy alloy for high frequencies having the above construction preferably has &Dgr;Tx of 60° C. (K) or more, and satisfies the relations 6 atomic %≦x≦10 atomic %, and 25 atomic %≦y≦32 atomic % in the composition formula T
100−x−y
M
x
B
y
.
The above-described high permeability metal glassy alloy for high frequencies may be represented by the following composition formula:
(Fe
1−a−b
Co
a
Ni
b
)
100−x−y
M
x
B
y
wherein M is at least one element of Zr, Nb, Ta, Hf, Mo, Ti, V, Cr and W, 0≦a≦0.85, 0≦b≦0.45, 4 atomic %≦x≦15 atomic %, and 22 atomic %≦y≦33 atomic %.
The high permeability glassy alloy for high frequencies having the above construction preferably has &Dgr;Tx of 70° C. (K) or more, and satisfies the relations 0≦a≦0.75, and 0≦b≦0.35 in the composition formula (Fe
1−a−b
Co
a
Ni
b
)
100−x−y
M
x
B
y
.
The high permeability glassy alloy for high frequencies having the above construction preferably has &Dgr;Tx of 80° C. (K) or more, and satisfies the relations 0.08≦a≦0.65, and 0≦b ≦0.2 in the composition formula (Fe
1−a−b
Co
a
Ni
b
)
100−x−y
M
x
B
y
.
The above-described high permeability metal glassy alloy for high frequencies may be represented by the following composition formula:
CO
100−z−v−w−q
E
z
M
v
B
w
L
q
wherein E is at least one element of Fe and Ni, M is at least one element of Zr, Nb, Ta, Hf, Mo, Ti, V, Cr and W, L is at lease one element of Cr, Mn, Ru, Rh, Pd, Os, Ir, Pt, Al, Ga, Si, Ge, C and P, 0 atomic %≦z≦30 atomic %, 4 atomic % ≦v ≦15 atomic %, 22 atomic % ≦w ≦33 atomic %, and 0 atomic %≦q≦10 atomic %.
Furthermore, the high permeability metal glassy alloy for high frequencies of the present invention may have a magnetic permeability of 20000 or more at 1 kHz.
REFERENCES:
patent: 4140525 (1979-02-01), Ray
patent: 4221592 (1980-09-01), Ray
patent: 4755239 (1988-07-01), O'Handley
patent: 5738733 (1998-04-01), Inoue
patent: 19802349 (1998-07-01), None
patent: 10-324939 (1998-01-01), None
patent: 11-131199 (1999-05-01), None
Derwent Abstract of Research Disclosure 356019 A, Dec. 10, 1993, Allied-Signal Inc.
Inoue Akihisa
Zhang Tao
Alps Electronic Co., Ltd.
Brinks Hofer Gilson & Lione
Oltmans Andrew L.
Sheehan John
LandOfFree
High permeability metal glassy alloy for high frequencies does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with High permeability metal glassy alloy for high frequencies, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High permeability metal glassy alloy for high frequencies will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2983546