Claims
- 1. A method of producing a flat-shaped fine Fe-Ni alloy powder comprising the steps of: preparing a melt of an Fe-Ni alloy material having a composition containing 70 to 90 wt % Ni, not more than 6 wt % Mo, and not more than 6 wt % Cu and which exhibits, in a bulk state, a saturated magnetostriction constant value falling within the range of .+-.15.times.10.sup.-6 ; obtaining a precursor powder from said Fe-Ni alloy melt by use of a water-atomizing process; mechanically pulverizing the material into fine powder having a mean particle size of 0.1 to 30 .mu.m and a mean thickness not greater than 2 .mu.m; and effecting an annealing on a portion comprising said fine powder without adding refractory material powder, at a temperature not less then about 300.degree. C. and not more than about 700.degree. C. and in a non-oxidizing atmosphere without causing substantial change in the shape of said fine powder, so as to reduce the coercive force to a level not higher than 400 A/m.
- 2. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 1, wherein the Fe-Ni alloy material contains from 0.1 wt % to 2 wt % of one or more of elements selected from the group consisting of B, P, As, Sb, Bi, S, Se and Te.
- 3. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 2, wherein said Fe-Ni alloy precursor powder is subjected to a heat treatment conducted in an atmosphere having a restrained oxygen potential, in advance of the pulverizing step.
- 4. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 3, wherein the pulverizing is conducted while fluidizing or moving the material powder.
- 5. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 3, wherein the pulverizing step is executed in the presence of a pulverizing aid.
- 6. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 2, wherein the pulverizing is conducted while fluidizing or moving the material powder.
- 7. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 2, wherein the pulverizing step is executed in the presence of a pulverizing aid.
- 8. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 1, wherein the pulverizing is conducted while fluidizing or moving the material powder.
- 9. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 8, wherein the pulverizing step is executed in the presence of a pulverizing aid.
- 10. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 1, wherein the pulverizing step is executed in the presence of a pulverizing aid.
- 11. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 1, wherein the composition consists essentially of 70 to 83 wt % Ni, 2-6 wt % Mo, 3-6 wt % Cu, 1-2 wt % Mn, not more than 0.05 wt % C, balance Fe and incidental impurities.
- 12. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 11, wherein the pulverizing is conducted while fluidizing or moving the material powder.
- 13. The method of producing a flat-shaped fine Fe-Ni alloy powder according to claim 11, wherein the pulverizing step is executed in the presence of a pulverizing aid.
Priority Claims (2)
Number |
Date |
Country |
Kind |
1-322365 |
Dec 1989 |
JPX |
|
2-89705 |
Apr 1990 |
JPX |
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Parent Case Info
This application is a continuation in part of application Ser. No. 07/868,212, filed Apr. 13, 1992, now abandoned, and a continuation in part of application Ser. No. 07/619,448, filed Nov. 29, 1990, now U.S. Pat. No. 5,135,586.
US Referenced Citations (1)
Number |
Name |
Date |
Kind |
1878589 |
Marris et al. |
Sep 1932 |
|
Foreign Referenced Citations (8)
Number |
Date |
Country |
62-23805 |
|
JPX |
63-35701 |
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JPX |
63-45706 |
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JPX |
58-59268 |
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JPX |
62-123494 |
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JPX |
62-54903 |
Jan 1987 |
JPX |
1-294801 |
Nov 1989 |
JPX |
706195 |
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SUX |
Continuation in Parts (2)
|
Number |
Date |
Country |
Parent |
868212 |
Apr 1992 |
|
Parent |
619448 |
Nov 1990 |
|