Aluminum alloy plate for magnetic disc substrate, method for manufacturing same, and method for manufacturing magnetic disc
US9613648B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 24, 2015 |
| Grant date | Apr 4, 2017 |
| Priority date | — |
| Expiry date | Sep 24, 2035 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC22F1/00
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
An aluminum alloy plate for a magnetic disk substrate with a flat and smooth ground surface, a production method by which the aluminum alloy plate can be produced at low cost and a magnetic disk are shown. An aluminum alloy plate for a magnetic disk substrate which comprises an aluminum alloy containing Mg: 3.0 to 8.0 mass % (hereinafter %), Cu: 0.005 to 0.150%, Zn: 0.05 to 0.60%, Cr: 0.010 to 0.300%, Fe: 0.001 to 0.030%, Si: 0.001 to 0.030%, (Ti+V+Zr): 0.0010 to 0.0100%, B: 0.0001 to 0.0010% with a balance being Al and inevitable impurities, wherein the density of a Ti—V—B—Zr-based inclusion having a maximum diameter exceeding 5 μm is 0 piece/6000 mm2 and the density of a Ti—V—B—Zr-based inclusion having a maximum diameter of 3 to 5 μm is 1 piece/6000 mm2 or less; a production method thereof; and a method for producing a magnetic disk.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.