Patent US2273619A successfully refreshed from Google Patents.
Patent US5136819A successfully refreshed from Google Patents.
US5136819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for mirror polishing of ti-made magnetic disk substrate
Assignee: JFE Engineering Corp
•
Filing: 1991-02-01
•
Granted: 1992-08-11
•
Expires: 2011-02-01
Abstract
Abstract According to a mirror surface polishing process of the present invention, it is possible to produce Ti-made magnetic disc substrate which have the excellent flatness degree and surface roughness in that the average roughness is not more than 0.05 μm and the flatness degree of the outer periphery is not more than 0.15 μm.
Inventors
- 👤 Masakuni Takagi
- 👤 Hiroyoshi Takeuchi
- 👤 Hideaki Fukai
- 👤 Toshio Sakiyama
- 👤 Hiroyoshi Suenaga
- 👤 Kuninori Minakawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:05
CPC Classifications
B; B24; B24B; B24B13/00; B24B37/00; B24B37/04; B24B37/042
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
142 words
A method of polishing a circular shaped titanium magnetic disk, comprising the steps of rough abrading at least one surface of the disk using a grinding wheel having a roughness of between 400 to 4,000 mesh, and an abrasion solution comprising alumina of 38 cm 3 and having a grain diameter of not more than 2 μm, and hydrogen peroxide of 200 ml; finish polishing the at least one surface using an abrasion cloth and controlling pressure on the at least one surface to be between 10 to 100 g/cm 2 ; and controlling the processing time to be between 5 and 60 minutes so as to produce an average surface roughness of not more than 0.05 μm, and a flatness, as measured between 40 mm to 46 mm from a center point of said disk, of not more than 0.15 μm.
Claim 2
Independent Claim
142 words
A method of polishing a circular shaped titanium magnetic disk, comprising the steps of rough abrading at least one surface of the disk using a grinding wheel having a roughness of between 400 to 4,000 mesh, and an abrasion solution comprising alumina of 38 cm 3 and having a grain diameter of not more than 2 μm, and hydrogen peroxide of 200 ml; finish polishing the at least one surface using an abrasion cloth and controlling pressure on the at least one surface to be between 10 to 100 g/cm 2 ; and controlling the processing time to be between 5 and 60 minutes so as to produce an average surface roughness of not more than 0.05 μm, and a flatness, as measured between 40 mm to 46 mm from a center point of said disk, of not more than 0.15 μm.
Claim 3
Dependent Claim
13 words
The method of claim 1, wherein the grinding wheel comprises grains of alumina.
Claim 4
Dependent Claim
14 words
The method of claim 1, wherein the grinding wheel comprises grains of silicon carbide.
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) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |