Method for pressing oxynitride glass, disk of oxynitride glass made by said method, and pressing die for said method
US6557378B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 2000 |
| Grant date | May 6, 2003 |
| Priority date | — |
| Expiry date | Aug 21, 2021 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B2215/44
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of producing a disk having a radius of r and a thickness of 2h from an oxynitride glass by pressing, said method being characterized in that the pressing load (F), the pressing temperature (T), and the pressing time (t) are defined by the expression below. where,F: pressing load (N)T: pressing temperature (° C.)t: pressing time (s)&pgr;: ratio of the circumference to its diameterr: radius of disk formed by pressing (mm)h: half a thickness of disk formed by pressing (mm)A: constant depending on glass composition (° C.) defined by 1450° C.≦A≦650° C.According to this method, it is possible to establish the optimum conditions for making disks from oxynitride glass, and it is possible to provide disks of oxynitride glass suitable for use as high-performance magnetic disk having a high specific rigidity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.