Patent US5131995A successfully refreshed from Google Patents.
US5131995A
Expired / Lapsed
US
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Method of manufacturing titanium magnetic disk substrate
Assignee: JFE Engineering Corp
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Filing: 1991-02-28
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Granted: 1992-07-21
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Expires: 2011-02-28
Abstract
Abstract After the surface roughness of a titanium substrate is set to be R max ≦0.08 μm, a hardened layer having a hardness of H v ≧250 is formed thereon to have a thickness of 50 to 250 μm by sputtering, thereby manufacturing a titanium magnetic disk substrate.
Inventors
- 👤 Hiroyoshi Suenaga
- 👤 Hideaki Fukai
- 👤 Toshio Sakiyama
- 👤 Kuninori Minakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:15
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/62; G11B5/73; G11B5/7368; G11B5/739; G11B5/73911; G11B5/73917; G11B5/73919
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
57 words
A method of manufacturing a titanium magnetic disk substrate, comprising the steps of: preparing a titanium substrate; setting the surface roughness of said titanium substrate to be R max ≦0.08 μm; and forming a hardened layer having a hardness of H v ≧250 on said titanium substrate to a thickness of 50 to 250 μm by sputtering.
Claim 2
Independent Claim
57 words
A method of manufacturing a titanium magnetic disk substrate, comprising the steps of: preparing a titanium substrate; setting the surface roughness of said titanium substrate to be R max ≦0.08 μm; and forming a hardened layer having a hardness of H v ≧250 on said titanium substrate to a thickness of 50 to 250 μm by sputtering.
Claim 3
Dependent Claim
15 words
A method according to claim 1, wherein said titanium substrate is formed of pure titanium.
Claim 4
Dependent Claim
28 words
A method according to claim 1, wherein said step of setting the surface roughness of said titanium substrate is achieved by polishing the surface of said titanium substrate.
Claim 5
Dependent Claim
16 words
A method according to claim 1, wherein said titanium substrate is formed of a titanium alloy.
Claim 6
Dependent Claim
12 words
A method according to claim 1, wherein said hardened layer is nonmagnetic.
Claim 7
Dependent Claim
31 words
A method according to claim 1, wherein the surface roughness of said titanium magnetic disk substrate is R max ≦0.1 μm after said step of forming a hardened layer is performed.
Claim 8
Independent Claim
76 words
A method of manufacturing a titanium magnetic disk, comprising the steps of: preparing a titanium substrate; setting the surface roughness of said titanium substrate to be R max ≦0.08 μm; forming a hardened layer having a hardness of H v ≧250 on said titanium substrate to a thickness of 50 to 250 μm by sputtering; and forming a magnetic film on said hardened layer after said hardened layer si formed, without performing an intermediate polishing step.
Claim 9
Independent Claim
76 words
A method of manufacturing a titanium magnetic disk, comprising the steps of: preparing a titanium substrate; setting the surface roughness of said titanium substrate to be R max ≦0.08 μm; forming a hardened layer having a hardness of H v ≧250 on said titanium substrate to a thickness of 50 to 250 μm by sputtering; and forming a magnetic film on said hardened layer after said hardened layer si formed, without performing an intermediate polishing step.
Claim 10
Dependent Claim
15 words
A method according to claim 7, wherein said titanium substrate is formed of pure titanium.
Claim 11
Dependent Claim
16 words
A method according to claim 7, wherein said titanium substrate is formed of a titanium alloy.
Claim 12
Dependent Claim
28 words
A method according to claim 7, wherein said step of setting the surface roughness of said titanium substrate is achieved by polishing the surface of said titanium substrate.
Claim 13
Dependent Claim
12 words
A method according to claim 7, wherein said hardened layer is nonmagnetic.
Claim 14
Dependent Claim
31 words
A method according to claim 7, wherein the surface roughness of said titanium magnetic disk substrate is R max ≦0.1 μm after said step of forming a hardened layer is performed.
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) | 1995-07-21 | 1996-01-20 | 1996-07-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-07-21 | 2000-01-20 | 2000-07-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-07-21 | 2004-01-20 | 2004-07-21 | $7700.00 | Window Closed / Lapsed |