Aluminum alloy substrate for magnetic disc and magnetic disc

Patent metadata

Field	Value
Publication number	US-12243570-B2
Application number	US-202318334651-A
Country	US
Kind code	B2
Filing date	Jun 14, 2023
Priority date	Dec 15, 2020
Publication date	Mar 4, 2025
Grant date	Mar 4, 2025

Abstract

An aluminum alloy substrate for a magnetic disc is made of an aluminum alloy, containing Fe: 1.80 mass % or less, Mn: 0.70 mass % or less, Ni: 2.50 mass % or less, Si: 2.50 mass % or less, Cu: 1.00 mass % or less, Zn: 0.48 mass % or less and Mg: 1.00 to 3.50 mass %, wherein a total content of Fe, Mn and Ni is 1.60 to 4.50 mass % and a mass ratio of Cu/Zn is 0.01 to 0.35 or 6.00 to 50.00, with a balance being Al and inevitable impurities.

First claim

The invention claimed is:

1. An aluminum alloy substrate for a magnetic disc made of an aluminum alloy, comprising Fe: 0.10 mass % or more and 1.80 mass % or less, Mn: 0.10 mass % or more and 0.70 mass % or less, Ni: 0.10 mass % more and 2.50 mass % or less, Si: 2.50 mass % or less, Cu: 0.003 mass % or more and 1.00 mass % or less, Zn: 0.003 more and 0.48 mass % or less and Mg: 1.00 to 3.50 mass %, wherein Fe, Mn and Ni has a total content that is 1.60 to 4.50 mass % and a mass ratio of Cu/Zn is 0.01 to 0.35 or 6.00 to 50.00, with a balance being Al and inevitable impurities.

2. The aluminum alloy substrate for a magnetic disc according to claim 1 , wherein the aluminum alloy further comprises one or two elements selected from the group consisting of Cr: 1.00 mass % or less and Zr: 1.00 mass % or less.

3. The aluminum alloy substrate for a magnetic disc according to claim 1 , wherein the aluminum alloy further comprises at least one element selected from the group consisting of Sr: 0.10 mass % or less, Na: 0.10 mass % or less and P: 0.10 mass % or less.

4. The aluminum alloy substrate for a magnetic disc according to claim 1 , wherein the aluminum alloy further comprises 0.0020 mass % or less of Be.

5. A magnetic disc comprising:
the aluminum alloy substrate for a magnetic disc according to claim 1 ;
a Ni—P plated layer on a surface of the aluminum alloy substrate for a magnetic disc; and
a magnetic body layer on the Ni—P plated layer.

6. The aluminum alloy substrate for a magnetic disc according to claim 1 , wherein the aluminum alloy is free of Cr.

7. The aluminum alloy substrate for a magnetic disc according to claim 1 , wherein the aluminum alloy includes 0.005 mass % or more and 0.06 mass % or less of Si.

Assignees

• Uacj Corp
• Furukawa Electric Co Ltd

Inventors

• Kitawaki Kotaro
• Hatakeyama Hideyuki
• Kumagai Wataru
• Sakamoto Ryo

Classifications

• G11B5/8404

  manufacturing base layers · CPC title

• G11B5/73913

  Composites or coated substrates · CPC title

• C22F1/00

  Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working (apparatus for mechanical working of metal B21, B23, B24) · CPC title

• C22F1/047

  of alloys with magnesium as the next major constituent · CPC title

• C22F1/04

  of aluminium or alloys based thereon · CPC title