Al-Mg-Si series alloy plate, method for manufacturing the same and Al-Mg-Si series alloy material

• US 20040079457A1
• Filed: 03/03/2003
• Published: 04/29/2004
• Est. Priority Date: 03/01/2002
• Status: Active Grant

• Current Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Original Assignee: Showa Denko KK (Resonac Holdings Corp.)
• Inventors: Akagi, Nobuhiko, Kimura, Kazuo
• Granted Patent: US 7,189,294 B2
• Time in Patent Office: Days
• US Class Current: 148/693
• CPC Class Codes: C22C 21/02 with silicon as the next major constituent
• CPC Class Codes: C22C 21/06 with magnesium as the next major constituent
• CPC Class Codes: C22C 21/08 with silicon
• CPC Class Codes: C22F 1/047 of alloys with magnesium as the next major constituent
• CPC Class Codes: C22F 1/05 of alloys of the Al-Si-Mg type, i.e. containing silicon and magnesium in approximately equal proportions

Abstract

A method for manufacturing an Al—Mg—Si series alloy plate includes the steps of hot-rolling and subsequently cold-rolling an Al—Mg—Si series alloy ingot. The Al—Mg—Si series alloy ingot consists of Si: 0.2 to 0.8 mass %, Mg: 0.3 to 1 mass %, Fe: 0.5 mass % or less, Cu: 0.5 mass % or less, at least one of elements selected from the group consisting of Ti: 0.1 mass % or less and B: 0.1 mass % or less and the balance being Al and inevitable impurities. Heat-treating for holding a rolled ingot at 200 to 400° C. for 1 hour or more is performed after a completion of the hot-rolling but before a completion of the cold-rolling.

Claims

1. A method for manufacturing an Al—

Mg—

Si series alloy plate, the method comprising;

hot-rolling and subsequently cold-rolling an Al—

Mg—

Si series alloy ingot,

wherein said Al—

Mg—

Si series alloy ingot consists of Si;

0.2 to 0.8 mass %, Mg;

0.3 to 1 mass %, Fe;

0.5 mass % or less, Cu;

0.5 mass % or less, at least one of elements selected from the group consisting of Ti;

0.1 mass % or less and B;

0.1 mass % or less and the balance being Al and inevitable impurities, and

wherein heat-treating for holding a rolled ingot at 200 to 400°

C. for 1 hour or more is performed after a completion of said hot-rolling but before a completion of said cold-rolling.

2. The method for manufacturing an Al—

Mg—

Si series alloy plate as recited in claim 1, wherein Mn and Cr contained as impurities in said ingot are controlled such that a content of Mn is 0.1 mass % or less and a content of Cr is 0.1 mass % or less.

3. The method for manufacturing an Al—

Mg—

Si series alloy plate as recited in claim 1 or 2, wherein said heat-treating is performed after said completion of said hot-rolling but before said cold-rolling.

4. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in claim 1 or 2, wherein said heat-treating is performed during said cold-rolling.

5. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 4, wherein said heat-treating is performed at 220 to 280°

C. for 1 to 10 hours.

6. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 5, further comprising homogenization processing of said alloy ingot performed at 500°

C. or above.

7. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 6, wherein said cold-rolling after said heat-treating is performed at a reduction ratio of 20% or more.

8. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in claim 7, wherein said reduction ratio is 30% or more.

9. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 8, further comprising final annealing performed at 200°

C. or below after said completion of said cold-rolling.

10. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in claim 9, wherein said final annealing is performed at 110 to 150°

C.

11. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 10, further comprising preheating said alloy ingot to 450 to 580°

C. before performing said hot-rolling.

12. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 11, wherein said hot-rolling includes a plurality of passes, and wherein a material temperature before one of said passes is set to be 450 to 350°

C. and a cooling rate after said one of said passes is set to be 50°

C./minute or more.

13. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a Si content of said alloy ingot is 0.32 to 0.6 mass %.

14. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a Mg content of said alloy ingot is 0.35 to 0.55 mass %.

15. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a Fe content of said alloy ingot is 0.1 to 0.25 mass %.

16. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a Cu content of said alloy ingot is 0.1 mass % or less.

17. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a Ti content of said alloy ingot is 0.005 to 0.05 mass %.

18. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a B content of said alloy ingot is 0.06 mass % or less.

19. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a Mn content of said alloy ingot is controlled to be 0.05 mass % or less.

20. The method for manufacturing said Al—

Mg—

Si series alloy plate as recited in any one of claims 1 to 12, wherein a Cr content of said alloy ingot is controlled to be 0.05 mass % or less.

24. An Al—

Mg—

Si series alloy plate manufactured by said method as recited in any one of claims 1 to 20.

25. The Al—

Mg—

Si series alloy plate as recited in claim 24, wherein said Al—

Mg—

Si series alloy plate is a member selected from the group consisting of a heat dissipation member, an electrically conductive member, a casing member, a light reflecting member or its supporting member.

26. The Al—

Mg—

Si series alloy plate as recited in claim 24, wherein said Al—

Mg—

Si series alloy plate is a member selected from the group consisting of a plasma display rear surface chassis member, a plasma display box member and a plasma display exterior member.

27. The Al—

Mg—

Si series alloy plate as recited in claim 24, wherein said Al—

Mg—

Si series alloy plate is a member selected from the group consisting of a liquid crystal display rear chassis member, a liquid crystal display bezel member, a liquid crystal display reflecting sheet member, a liquid crystal display reflecting sheet supporting member and a liquid crystal display box material.

21. An Al—

Mg—

Si series alloy material consisting of Si;

0.2 to 0.8 mass %, Mg;

0.3 to 1 mass %, Fe;

0.5 mass % or less, Cu;

0.5 mass % or less, at least one of elements selected from the group consisting of Ti;

0.1 mass % or less and B;

0.1 mass %, and the balance being Al and inevitable impurities, wherein electrical conductivity of said alloy material is 55 to 60% (IACS).

22. The Al—

Mg—

Si series alloy material as recited in claim 21, wherein tensile strength of said alloy material is 140 to 240 N/mm².

23. The Al—

Mg—

Si series alloy material as recited in claim 21 or 22, wherein Mn and Cr as impurities of said alloy are controlled to be Mn;

0.1 mass % or less and Cr;

0.1 mass % or less.