US5022939A
Expired / Lapsed
US
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Permanent magnets
Assignee: TDK Corp
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Filing: 1989-05-02
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Granted: 1991-06-11
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Expires: 2009-05-02
Abstract
Abstract A permanent magnet material having high coercivity and energy product is provided which contains rare earth elements, boron, at least one element of Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W, optional nickel, and a balance of Fe or Fe and Co, and consists of a primary phase of substantially tetragonal grain structure, or a mixture of such a primary phase and an amorphous or crystalline rare earth element-poor auxiliary phase wherein the volume ratio of auxiliary phase to primary phase has a specific relationship to other parameters.
Inventors
- 👤 Koichi Yajima
- 👤 Osamu Kohmoto
- 👤 Tetsuhito Yoneyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 16:31
CPC Classifications
B; B22; B22F; B22F9/00; B22F9/002; B22F9/008; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/047; H01F1/053; H01F1/055; H01F1/057; H01F1/0571; H01F1/0575; H01F1/0578
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
97 words
A permanent magnet material which is prepared by rapid quenching from a molten alloy having a composition represented by the formula: R.sub.x T.sub.(100-x-y-z-w) B.sub.y M.sub.z Ni.sub.w wherein R is at least one member selected from the rare earth elements including Y, T is Fe or a mixture of Fe and Co, M is at least one member selected from the group consisting of T, V, Cr, Zr, Nb, Hf, Ta and W, letters x,y,z, and w represent atom percents of the corresponding elements and have positive values with the proviso that w can be equal to zero,
Claim 2
Dependent Claim
97 words
A permanent magnet material which is prepared by rapid quenching from a molten alloy having a composition represented by the formula: R.sub.x T.sub.(100-x-y-z-w) B.sub.y M.sub.z Ni.sub.w wherein R is at least one member selected from the rare earth elements including Y, T is Fe or a mixture of Fe and Co, M is at least one member selected from the group consisting of T, V, Cr, Zr, Nb, Hf, Ta and W, letters x,y,z, and w represent atom percents of the corresponding elements and have positive values with the proviso that w can be equal to zero,
Claim 3
Dependent Claim
78 words
5 ≦ x < 11.76, 2 ≦ y < 15, 0 < z ≦ 15, and 0 < z+w ≦ 30, and consisting essentially of a primary phase of substantially tetragonal grain structure and at least one auxiliary phase selected from amorphous and crystalline R-poor auxiliary phases, said auxiliary phase being present as a grain boundary layer, the atomic ratio of the R content of the auxiliary phase to that of the primary phase being up to 9/10.
Claim 4
Dependent Claim
78 words
5 ≦ x < 11.76, 2 ≦ y < 15, 0 < z ≦ 15, and 0 < z+w ≦ 30, and consisting essentially of a primary phase of substantially tetragonal grain structure and at least one auxiliary phase selected from amorphous and crystalline R-poor auxiliary phases, said auxiliary phase being present as a grain boundary layer, the atomic ratio of the R content of the auxiliary phase to that of the primary phase being up to 9/10.
Claim 5
Dependent Claim
34 words
The permanent magnet material of claim 1 wherein the quotient of the volume ratio of auxiliary phase to primary phase (v) divided by the value given by the formula: [0.1176(100-z)-x]/x is up to 2.
Claim 6
Dependent Claim
39 words
The permanent magnet material of claim 2 wherein the quotient of the volume ratio of auxiliary phase to primary phase (v) divided by the value given by the formula: [0.1176(100-z)-x]/x ranges from 1 to 2 and z ≦ 10.
Claim 7
Dependent Claim
34 words
The permanent magnet material of claim 2 wherein the quotient of the volume ratio of auxiliary phase to primary phase (v) divided by the value given by the formula: [0.1176(100-z)-x]/x is less than unity.
Claim 8
Dependent Claim
35 words
The permanent magnet material of claim 2 wherein the quotient of the volume ratio of auxiliary phase to primary phase (v) divided by the value given by the formula: [0.1176(100-z)-x]/x ranges from 0.15 to 0.95.
Claim 9
Dependent Claim
34 words
The permanent magnet material of claim 1 wherein the quotient of the volume ratio of auxiliary phase to primary phase (v) divided by the value given by the formula: (11.76-x)/x is up to 2.
Claim 10
Dependent Claim
34 words
The permanent magnet material of claim 6 wherein the quotient of the volume ratio of auxiliary phase to primary phase (v) divided by the value given by the formula: (11.76-x)/x is up to 1.
Claim 11
Dependent Claim
13 words
The permanent magnet material of claim 1 wherein 5.5 ≦ x ≦ 11.
Claim 12
Dependent Claim
22 words
The permanent magnet material of claim 1 wherein the primary phase has an average grain size of from 0.01 to 3 μm.
Claim 13
Dependent Claim
25 words
The permanent magnet material of claim 1 wherein the auxiliary phase forms a grain boundary layer having an average breadth of up to 0.3 μm.
Claim 14
Dependent Claim
22 words
The permanent magnet material of claim 1 wherein the primary phase has an R content of from 6 to 11.76 atom %.
Claim 15
Dependent Claim
19 words
The permanent magnet material of claim 1 in the form of a ribbon which is prepared by rapid quenching.
Claim 16
Dependent Claim
12 words
The permanent magnet material of claim 1 in the form of powder.
Claim 17
Dependent Claim
49 words
The permanent magnet material of claim 2 which is obtained by rapid quenching from a molten alloy such that the quotient of the volume ratio of auxiliary phase to primary phase, v, divided by the value given by the formula: [0.1176(100-z)-x]/x may range from more than 0 to 2.
Claim 18
Dependent Claim
53 words
The permanent magnet material of claim 2 which is obtained by rapid quenching from a molten alloy and then heat treating such that the quotient of the volume ratio of auxiliary phase to primary phase, v, divided by the value given by the formula: [0.1176(100-z)-x]/x may range from more than 0 to 2.
Claim 19
Dependent Claim
27 words
The permanent magnet material of claim 1 wherein the permanent magnet material being comminuted into particles having M or M and Ni present on the surface thereof.
Claim 20
Dependent Claim
27 words
The permanent magnet material of claim 18 wherein the M content on the surface of particles is greater than the value of z for the entire material.
Claim 21
Dependent Claim
14 words
The permanent magnet material of claim 1 wherein B is partially replaced by P.
Claim 22
Dependent Claim
50 words
The permanent magnet material of claim 1 wherein M is a mixture of (a) at least one member selected from the group consisting of Ti, V, Cr, Zr, Nb, Mo, Hf, Ta and W and (b) at least one member selected from the group consisting of Cu, Mn and Ag.
Claim 23
Dependent Claim
23 words
A permanent magnet which is obtained by compacting the permanent magnet material of any one of claims 1 to 21 in powder form.
Claim 24
Dependent Claim
26 words
A permanent magnet which is obtained by hot plastic processing of the permanent magnet material of any one of claims 1 to 21 in powder form.
Claim 25
Dependent Claim
24 words
A permanent magnet comprising in admixture the permanent magnet material of any one of claims 1 to 21 in powder form and a binder.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-06-10 | 1994-12-10 | 1995-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-06-10 | 1998-12-10 | 1999-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-06-10 | 2002-12-10 | 2003-06-11 | $7700.00 | Window Closed / Lapsed |