US3661570A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic head material method
Assignee: RCA Corp
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Filing: 1970-04-03
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Granted: 1972-05-09
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Expires: 1990-04-03
Abstract
Abstract A process is described for providing a magnetic transducer material useful for the signal heads of a recorder-reproduced system. The process results in a material for a head core which consists of a majority or first phase of an alloy of iron, silicon and aluminum with an abrasion resistant second phase disposed in the grain boundaries throughout the first phase material.
Inventors
- 👤 Herbert Irwin Moss
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:00
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/127; Y; Y10; Y10S; Y10S428/00; Y10S428/922; Y10S428/9265; Y10S428/928; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/4902; Y10T29/49021; Y10T29/49032; Y10T29/49034
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
34 words
The invention according to claim 1, wherein; a bulk of said first phase alloy is crushed to provide said granular sample for milling, said sample having a granular size no greater than 840 microns.
Claim 2
Dependent Claim
41 words
The invention according to claim 1, wherein following the steps of separating the particles from said milling solution and drying, the particles are passed through a sieve to provide a quantity of particles having a size no greater than 20 microns.
Claim 3
Dependent Claim
26 words
The invention according to claim 1, wherein said milling solution is no less than 80 volume percent alcohol and no more than 20 volume percent water.
Claim 4
Dependent Claim
13 words
The invention according to claim 1, wherein said non-aqueous solvent is ethyl alcohol.
Claim 5
Dependent Claim
39 words
The invention according to claim 1, wherein said hot pressing step includes: molding said particles at a pressure, temperature and for a time to provide a compacted body of said particles which has a porosity less than 1 percent.
Claim 6
Dependent Claim
36 words
The invention according to claim 6, wherein said hot pressing is performed utilizing a pressure in the range of 3,500 psi to 60,000 psi and a temperature in the range of 750* C. to 1,100* C.
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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |