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Patent US5120615A successfully refreshed from Google Patents.
US5120615A
Expired / Lapsed
US
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Magnetic disk substrate and method of manufacturing the same
Assignee: JFE Engineering Corp
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Filing: 1990-06-12
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Granted: 1992-06-09
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Expires: 2010-06-12
Abstract
Abstract A magnetic disk substrate composition 0.5 wt % to 1.0 wt % of Mo, 0.03 wt % to 0.5 wt % of O+2N+0.75C, and a balance of Ti. The alloy sheet having a composition of above range is cold-rolled at a rolling ratio of 30% or more to form a magnetic disk substrate material, and the material is thermal-flattened under the following condition: 500≦T≦-(150/11)·t+7850/11 1≦t where T represents a thermal-flattening temperature (°C.), and t represents a thermal-flattening time (houre), thereby obtaining a magnetic disk substrate having the average grain size of 30 μm or less.
Inventors
- 👤 Hideaki Fukai
- 👤 Hiroyoshi Suenaga
- 👤 Kuninori Minakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:32
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/84; G11B5/8404; G11B5/62; G11B5/73; G11B5/739; G11B5/73911; G11B5/73917; G11B5/73919
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
66 words
A titanium alloy magnetic disk substrate comprising 0.5 wt. % to 1.0 wt. % of Mo, and containing oxygen, nitrogen and carbon in an amount such that O+2N+0.75C is from 0.3 wt. % to 0.5 wt. % of said titanium alloy, and the balance of Ti wherein O is the weight of oxygen, N is the weight of nitrogen and C is the weight of carbon.
Claim 2
Dependent Claim
66 words
A titanium alloy magnetic disk substrate comprising 0.5 wt. % to 1.0 wt. % of Mo, and containing oxygen, nitrogen and carbon in an amount such that O+2N+0.75C is from 0.3 wt. % to 0.5 wt. % of said titanium alloy, and the balance of Ti wherein O is the weight of oxygen, N is the weight of nitrogen and C is the weight of carbon.
Claim 3
Dependent Claim
21 words
The titanium alloy magnetic disk substrate according to claim 1, having an average grain size of no more than 30 μm.
Claim 4
Dependent Claim
31 words
The titanium alloy magnetic disk substrate according to claim 2 which consists essentially of 0.53 Mo wt. %, 0.08 O wt. %, 0.015 N wt. % and 0.04 C wt. %.
Claim 5
Dependent Claim
31 words
The titanium alloy magnetic disk substrate according to claim 2 which consists essentially of 0.75 Mo wt. %, 0.08 O wt. %, 0.018 N wt. % and 0.04 C wt. %.
Claim 6
Dependent Claim
31 words
The titanium alloy magnetic disk substrate according to claim 2 which consists essentially of 0.92 Mo wt. %, 0.09 O wt. %, 0.015 N wt. % and 0.07 C wt. %.
Claim 7
Dependent Claim
31 words
The titanium alloy magnetic disk substrate according to claim 2 which consists essentially of 0.88 Mo wt. %, 0.32 O wt. %, 0.016 N wt. % and 0.04 C wt. %.
Claim 8
Dependent Claim
31 words
The titanium alloy magnetic disk substrate according to claim 2 which consists essentially of 0.90 Mo wt. %, 0.40 O wt. %, 0.018 N wt. % and 0.04 C wt. %.
References Cited (Backward Citations)
JPS5274746A
Cited
JPS52105804A
Cited
JPS59151335A
Cited
JPS61199224A
Cited
JPS62274687A
Cited
JPH01112521A
Cited
US4990362A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-09 | 1995-12-09 | 1996-06-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-09 | 1999-12-09 | 2000-06-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-09 | 2003-12-09 | 2004-06-09 | $7700.00 | Window Closed / Lapsed |