Claims
- 1. A ferromagnetic powder product comprising an alloy of:
- about 10 to 33 weight % iron
- about 8 to 30 weight % nickel
- about 50 to 82 weight % of cobalt said powder having a maximum average dimension of 5 microns, and which has:
- a coercivity of at least 500
- a magnetic moment of at least 140 and a
- squareness of at least 0.5.
- 2. A product as defined in claim 1 but wherein said iron is from 10 to 24% and the nickel is at least 12%.
- 3. A product as defined in claim 1 which, when exposed to 50% relative humidity at 166.degree. F. for 100 hours retains at least 50% of the specific magnetic moment which characterized it before said exposure.
- 4. A product as defined in claim 1 wherein said powder has a squareness of at least 0.72.
- 5. A product as defined in claim 2 which, when exposed to 50% relative humidity at 166.degree. F. for 100 hours retains at least 50% of the specific magnetic moment which characterized it before said exposure.
- 6. A product as defined in claim 2 wherein said powder is formed of acicular particles having average length-to-width ratio of at least 3:1 and have length of from 0.3 to about 5 microns and has a squareness of at least 0.72.
- 7. A product as defined in claim 3 wherein said powder is formed of acicular particles having average length-to-width ratio of at least 3:1 and have length of from 0.3 to about 5 microns and has a squareness of at least 0.72.
- 8. A ferromagnetic powder product as defined in claim 1 wherein the alloy consists essentially of
- about 18 weight % iron
- about 18 weight % nickel
- about 64 weight % cobalt.
- 9. The ferro magnetic powder product defined in claim 5 wherein the alloy consists essentially of:
- about 18 weight % iron
- about 18 weight % manganese
- about 64 weight % cobalt.
- 10. The ferromagnetic powder product defined in claim 1 wherein the nickel is substituted for by manganese.
- 11. A magnetic recording medium of the type comprising a metallic powder dispersed in a polymeric binder wherein said powder is formed of an alloy consisting essentially of
- about 10 to 33 weight % iron,
- about 8 to 30 weight % nickel, and
- about 50 to 82 weight % cobalt;
- and wherein said powder is characterized by
- a. a minimum squareness of about 0.5
- b. a minimum coercive force about 500 oersteds, a specific magnetic moment of 140 to 190, and a corrosion resistance characterized by the ability to maintain at least 50% of its specific magnetic moment when exposed to 50% relative humidity at 166.degree. F. for 100 hours.
- 12. A recording medium as defined in claim 11 wherein the metallic powder has a squareness of at least 0.72.
- 13. A recording medium as defined in claim 12 wherein said iron is from 10 to 24% and the nickel is at least 12%.
- 14. A recording medium as defined in claim 13 wherein the metallic powder has a squareness of at least 0.72.
- 15. A recording medium as described in claim 11 wherein some of the nickel is replaced with manganese.
- 16. A recording medium as described in claim 11 wherein at least 70% of said specific magnetic moment is retained after said exposure.
- 17. A recording medium as described in claim 13 wherein at least 70% of said specific magnetic moment is retained after said exposure.
- 18. The recording medium defined in claim 11 wherein the alloy consists essentially of:
- about 18 weight % iron
- about 18 weight % nickel
- about 64 weight % cobalt.
- 19. The magnetic recording medium defined in claim 13 wherein the alloy consists essentially of:
- about 18 weight % iron
- about 18 weight % nickel
- about 64 weight % cobalt.
- 20. The medium defined in claim 14 wherein the alloy consists essentially of:
- about 18 weight % iron
- about 18 weight % nickel
- about 64 weight % cobalt.
RELATED APPLICATIONS
This Application is a continuation of commonly owned and co-pending Ser. No. 411,670 filed Nov. 1, 1973, now abandoned, and a continuation-in-part of commonly owned (and co-pending with Ser. No. 411,670) Ser. No. 401,636 filed on Sept. 28, 1973. Ser. No. 401,636 is now U.S. Pat. No. 3,909,240.
US Referenced Citations (7)
Continuations (1)
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Number |
Date |
Country |
Parent |
411670 |
Nov 1973 |
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