US4882236A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Rigid magnetic recording disks and method of producing same
Assignee: Olin Corp
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Filing: 1988-02-10
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Granted: 1989-11-21
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Expires: 2008-02-10
Abstract
Abstract The present invention discloses a rigid magnetic recording disk and a method of making the same. The substrate is formed by metallurgically bonding at least a first and second layer of clad materials. The hardness and mechanical strength of the first layer is substantially greater than the second layer. The first layer has a thickness which is from about 0.2% to about 20% the thickness of the second layer. The unbonded surface of the first layer is substantially flat and asperity free. The second layer is less dense than the first layer. A magnetic layer is deposited on the unbonded surface of the first layer.
Inventors
- 👤 Charles W. Smith
- 👤 Sheldon H. Butt
- 👤 Eugene Shapiro
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 22:58
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/739; G11B5/73911; G11B5/73917; G11B5/73919; G11B5/73913; Y; Y10; Y10T; Y10T428/00; Y10T428/12; Y10T428/12493; Y10T428/12736; Y10T428/1275; Y10T428/12771; Y10T428/12861; Y10T428/12903; Y10T428/1291
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
142 words
A substrate for a rigid magnetic recording disk, said substrate comprising: a clad material having at least first and second layers, each of said layers having first and second opposing surfaces; said first layer comprising a copper-based alloy containing nickel; said second layer comprising a material selected from the group consisting of aluminum and aluminum alloys; said first surface of said first layer being substantially asperity free; said second surface of said first layer being metallurgically bonded to at least one of said surfaces of said second layer without any substantial intermetallic formation; the thickness of said first layer being from about 0.2% to about 20% of the thickness of said second layer; the hardness and the mechanical strength of said first layer being substantially greater than said second layer; and said second layer being substantially less dense than said first layer.
Claim 2
Dependent Claim
142 words
A substrate for a rigid magnetic recording disk, said substrate comprising: a clad material having at least first and second layers, each of said layers having first and second opposing surfaces; said first layer comprising a copper-based alloy containing nickel; said second layer comprising a material selected from the group consisting of aluminum and aluminum alloys; said first surface of said first layer being substantially asperity free; said second surface of said first layer being metallurgically bonded to at least one of said surfaces of said second layer without any substantial intermetallic formation; the thickness of said first layer being from about 0.2% to about 20% of the thickness of said second layer; the hardness and the mechanical strength of said first layer being substantially greater than said second layer; and said second layer being substantially less dense than said first layer.
Claim 3
Dependent Claim
19 words
A substrate in accordance with claim 1 wherein said copper-based alloy comprises from about 15% to about 30% nickel.
Claim 4
Dependent Claim
157 words
A rigid magnetic recording disk comprising: a magnetic layer; a substrate supporting said magnetic layer; said substrate being formed by a clad material having at least first and second layers, each of said layers having first and second opposing surfaces; said first layer comprising a copper-based alloy containing nickel; said second layer comprising a material selected from the group consisting of aluminum and aluminum alloys; said first surface of said first layer being substantially asperity free and having said magnetic layer thereon; said second surface of said first layer being metallurgically bonded to at least one of said surfaces of said second layer without any substantial intermetallic formation; the thickness of said first layer being from about 0.2% to about 20% of the thickness of said second layer; the hardness and the mechanical strength of said first layer being substantially greater than said second layer; and said second layer being substantially less dense than said first layer.
Claim 5
Dependent Claim
157 words
A rigid magnetic recording disk comprising: a magnetic layer; a substrate supporting said magnetic layer; said substrate being formed by a clad material having at least first and second layers, each of said layers having first and second opposing surfaces; said first layer comprising a copper-based alloy containing nickel; said second layer comprising a material selected from the group consisting of aluminum and aluminum alloys; said first surface of said first layer being substantially asperity free and having said magnetic layer thereon; said second surface of said first layer being metallurgically bonded to at least one of said surfaces of said second layer without any substantial intermetallic formation; the thickness of said first layer being from about 0.2% to about 20% of the thickness of said second layer; the hardness and the mechanical strength of said first layer being substantially greater than said second layer; and said second layer being substantially less dense than said first layer.
Claim 6
Dependent Claim
19 words
A disk in accordance with claim 3 wherein said copper-based alloy comprises from about 15% to about 30% nickel.
Claim 7
Dependent Claim
152 words
A process for forming a rigid magnetic recording disk comprising: providing a substrate; said step of providing a substrate comprising providing a first layer having first and second surfaces, said first surface of said first layer being substantially asperity free; providing a second layer having first and second surfaces, with the thickness of said first layer being from about 0.2% to about 20% greater than the thickness of said second layer, and with the hardness and the strength for said first layer being greater than that said second layer; said first layer comprising a copper-based alloy containing nickel; said second layer comprising a material selected from the group consisting of aluminum and aluminum alloys; metallurgically bonding said second surface of said first layer to at least one of said surfaces of said second layer without any substantial intermetallic formation; and forming a magnetic layer on said first surface of said first layer.
Claim 8
Dependent Claim
152 words
A process for forming a rigid magnetic recording disk comprising: providing a substrate; said step of providing a substrate comprising providing a first layer having first and second surfaces, said first surface of said first layer being substantially asperity free; providing a second layer having first and second surfaces, with the thickness of said first layer being from about 0.2% to about 20% greater than the thickness of said second layer, and with the hardness and the strength for said first layer being greater than that said second layer; said first layer comprising a copper-based alloy containing nickel; said second layer comprising a material selected from the group consisting of aluminum and aluminum alloys; metallurgically bonding said second surface of said first layer to at least one of said surfaces of said second layer without any substantial intermetallic formation; and forming a magnetic layer on said first surface of said first layer.
Claim 9
Dependent Claim
19 words
A process in accordace with claim 5 wherein said copper-based alloy comprises from about 15% to about 30% nickel.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-11-20 | 1993-05-22 | 1993-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-20 | 1997-05-22 | 1997-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-20 | 2001-05-22 | 2001-11-21 | $7700.00 | Window Closed / Lapsed |