U.S. patent application number 10/692708 was filed with the patent office on 2004-06-24 for a1-mg-si series alloy plate excellent in thermal conductivity and strength, and method of manufacturing the same.
This patent application is currently assigned to SHOWA DENKO K.K.. Invention is credited to Kimura, Kazuo, Shimao, Ryosuke, Taguchi, Kyohei, Tsukuda, Ichizo.
Application Number | 20040118493 10/692708 |
Document ID | / |
Family ID | 32595614 |
Filed Date | 2004-06-24 |
United States Patent
Application |
20040118493 |
Kind Code |
A1 |
Kimura, Kazuo ; et
al. |
June 24, 2004 |
A1-Mg-Si series alloy plate excellent in thermal conductivity and
strength, and method of manufacturing the same
Abstract
An Al--Mg--Si series alloy ingot consisting essentially of Si:
0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt % or less, Cu:
0.20 wt % or less and the balance being aluminum and inevitable
impurities, or an Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or less and the
balance being aluminum and inevitable impurities, is prepared. The
alloy ingot is homogenized, then subjected to rough hot rolling and
finish hot rolling, and finally to cold rolling. One of plural
passes performed at the rough hot rolling is controlled such that
material temperature immediately before the aforementioned one of
passes is from 350 to 440 .degree. C., cooling rate during the
aforementioned one of plural passes is 50.degree. C./min or more,
material temperature immediately after the aforementioned one of
passes is from 250 to 340.degree. C. and plate thickness
immediately after the aforementioned passes is 15 mm or less. The
cold rolling is controlled such that rolling reduction is 30% or
more. Furthermore, the cold rolled plate is subjected to final
aging at a temperature of 180.degree. C. or below, or is not
subjected to final aging.
Inventors: |
Kimura, Kazuo; (Yoshinogun,
JP) ; Tsukuda, Ichizo; (Osaka, JP) ; Taguchi,
Kyohei; (Osaka, JP) ; Shimao, Ryosuke; (Osaka,
JP) |
Correspondence
Address: |
Vasilios D. Dossas
Niro, Scavone, Haller & Niro
Suite 4600
181 West Madison Street
Chicago
IL
60602
US
|
Assignee: |
SHOWA DENKO K.K.
Tokyo
JP
|
Family ID: |
32595614 |
Appl. No.: |
10/692708 |
Filed: |
October 24, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10692708 |
Oct 24, 2003 |
|
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|
09818070 |
Mar 27, 2001 |
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6660111 |
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Current U.S.
Class: |
148/692 ;
148/415; 148/440; 148/693 |
Current CPC
Class: |
C22C 21/08 20130101;
C22F 1/05 20130101 |
Class at
Publication: |
148/692 ;
148/415; 148/440; 148/693 |
International
Class: |
C22C 021/02 |
Claims
What is claimed is:
1. A method of manufacturing an Al--Mg--Si series alloy plate
excellent in thermal conductivity and strength, the method
comprising the steps of: preparing Al--Mg--Si series alloy ingot
consisting essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %,
Fe: 0.5 wt % or less, Cu: 0.20 wt % or less and the balance being
aluminum and inevitable impurities; homogenizing said alloy ingot;
subjecting said alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate; subjecting said roughly hot rolled plate
to finish hot rolling to obtain a finished hot rolled plate; and
subjecting said finished hot rolled plate to cold rolling, wherein
one of plural passes performed at said rough hot rolling is
controlled such that material temperature immediately before said
one of plural passes is from 350 to 440.degree. C., cooling rate
during said one of plural passes is 50.degree. C./min or more,
material temperature immediately after said one of plural passes is
from 250 to 340.degree. C. and plate thickness immediately after
said one of plural passes is 10 mm or more but not larger than 15
mm, wherein said cold rolling is controlled such that rolling
reduction is 30% or more, and wherein said cold rolled plate is
subjected to final aging at a temperature of 180.degree. C. or
below, or is not subjected to final aging.
2. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein Si content of said Al--Mg--Si series
alloy ingot is from 0.32 to 0.60 wt %.
3. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein Mg content of said Al--Mg--Si series
alloy ingot is from 0.35 to 0.55 wt %.
4. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C.
5. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein said plate thickness immediately after
said one of plural passes is 12 mm or less.
6. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C., and
wherein said plate thickness immediately after said one of plural
passes is 12 mm or less.
7. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein said rolling reduction of said cold
rolling is 50% or more.
8. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C., and
wherein said rolling reduction of said cold rolling is 50% or
more.
9. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein said plate thickness immediately after
said one of plural passes is 12 mm or less, and wherein said
rolling reduction of said cold rolling is 50% or more.
10. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 1, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C.,
wherein said plate thickness immediately after said one of said
plural passes is 12 mm or less, and wherein said rolling reduction
of said cold rolling is 50% or more.
11. A method of manufacturing an Al--Mg--Si series alloy plate
excellent in thermal conductivity and strength, the method
comprising the steps of: preparing Al--Mg--Si series alloy ingot
consisting essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %,
Fe: 0.5 wt % or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or less
and the balance being aluminum and inevitable impurities;
homogenizing said alloy ingot; subjecting said alloy ingot to rough
hot rolling to obtain a roughly hot rolled plate; subjecting said
roughly hot rolled plate to finish hot rolling to obtain a finished
hot rolled plate; and subjecting said finished hot rolled plate to
cold rolling, wherein one of plural passes performed at said rough
hot rolling is controlled such that material temperature
immediately before said one of plural passes is from 350 to
440.degree. C., cooling rate during said one of plural passes is
50.degree. C./min or more, material temperature immediately after
said one of plural passes is from 250 to 340.degree. C. and plate
thickness immediately after said one of plural passes is 15 mm or
less, wherein said cold rolling is controlled such that rolling
reduction is 30% or more, and wherein said cold rolled plate is
subjected to final aging at a temperature of 180.degree. C. or
below, or is not subjected to final aging.
12. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein Si content of said Al--Mg--Si series
alloy ingot is from 0.32 to 0.60 wt %.
13. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein Mg content of said Al--Mg--Si series
alloy ingot is from 0.35 to 0.55 wt %.
14. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C.
15. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein said plate thickness immediately after
said one of plural passes is 12 mm or less.
16. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C., and
wherein said plate thickness immediately after said one of plural
passes is 12 mm or less.
17. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein said rolling reduction of said cold
rolling is 50% or more.
18. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C., and
wherein said rolling reduction of said cold rolling is 50% or
more.
19. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein said plate thickness immediately after
said one of plural passes is 12 mm or less, and wherein said
rolling reduction of said cold rolling is 50% or more.
20. The method of manufacturing an Al--Mg--Si series alloy plate as
recited in claim 11, wherein said material temperature immediately
before said one of plural passes is from 380 to 420.degree. C.,
wherein said plate thickness immediately after said one of said
plural passes is 12 mm or less, and wherein said rolling reduction
of said cold rolling is 50% or more.
21. An Al--Mg--Si series alloy plate excellent in thermal
conductivity and strength manufactured by a method, the method
comprising the steps of: preparing Al--Mg--Si series alloy ingot
consisting essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %,
Fe: 0.5 wt % or less, Cu: 0.20 wt % or less and the balance being
aluminum and inevitable impurities; homogenizing said alloy ingot;
subjecting said alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate; subjecting said roughly hot rolled plate
to finish hot rolling to obtain a finished hot rolled plate; and
subjecting said finished hot rolled plate to cold rolling, wherein
one of plural passes performed at said rough hot rolling is
controlled such that material temperature immediately before said
one of plural passes is from 350 to 440.degree. C., cooling rate
during said one of plural passes is 50.degree. C./min or more,
material temperature immediately after said one of plural passes is
from 250 to 340.degree. C. and plate thickness immediately after
said one of plural passes is 10 mm or more but not larger than 15
mm, wherein said cold rolling is controlled such that rolling
reduction is 30% or more, and wherein said cold rolled plate is
subjected to final aging at a temperature of 180.degree. C. or
below, or is not subjected to final aging.
22. The Al--Mg--Si series alloy plate as recited in claim 21,
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.
23. The Al--Mg--Si series alloy plate as recited in claim 22,
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.
24. The Al--Mg--Si series alloy plate as recited in claim 22,
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.
25. An Al--Mg--Si series alloy plate excellent in thermal
conductivity and strength manufactured by a method, the method
comprising the steps of: preparing Al--Mg--Si series alloy ingot
consisting essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %,
Fe: 0.5 wt % or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or less
and the balance being aluminum and inevitable impurities;
homogenizing said alloy ingot; subjecting said alloy ingot to rough
hot rolling to obtain a roughly hot rolled plate; subjecting said
roughly hot rolled plate to finish hot rolling to obtain a finished
hot rolled plate; and subjecting said finished hot rolled plate to
cold rolling, wherein one of plural passes performed at said rough
hot rolling is controlled such that material temperature
immediately before said one of plural passes is from 350 to
440.degree. C., cooling rate during said one of plural passes is
50.degree. C./min or more, material temperature immediately after
said one of plural passes is from 250 to 340.degree. C. and plate
thickness immediately after said one of plural passes is 15 mm or
less, wherein said cold rolling is controlled such that rolling
reduction is 30% or more, and wherein said cold rolled plate is
subjected to final aging at a temperature of 180.degree. C. or
below, or is not subjected to final aging.
26. The Al--Mg--Si series alloy plate as recited in claim 25,
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.
27. The Al--Mg--Si series alloy plate as recited in claim 26,
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.
28. The Al--Mg--Si series alloy plate as recited in claim 26,
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.
29. A plasma display comprising a rear chassis member, a box member
and an exterior member, wherein at least one of said rear chassis
member, said box member and said exterior member is constituted by
an Al--Mg--Si series alloy plate manufactured by a method, the
method comprising the steps of: preparing Al--Mg--Si series alloy
ingot consisting essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9
wt %, Fe: 0.5 wt % or less, Cu: 0.20 wt % or less and the balance
being aluminum and inevitable impurities; homogenizing said alloy
ingot; subjecting said alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate; subjecting said roughly hot rolled plate
to finish hot rolling to obtain a finished hot rolled plate; and
subjecting said finished hot rolled plate to cold rolling, wherein
one of plural passes performed at said rough hot rolling is
controlled such that material temperature immediately before said
one of plural passes is from 350 to 440.degree. C., cooling rate
during said one of plural passes is 50.degree. C./min or more,
material temperature immediately after said one of plural passes is
from 250 to 340.degree. C. and plate thickness immediately after
said one of plural passes is 10 mm or more but not larger than 15
mm, wherein said cold rolling is controlled such that rolling
reduction is 30% or more, and wherein said cold rolled plate is
subjected to final aging at a temperature of 180.degree. C. or
below, or is not subjected to final aging.
30. A liquid crystal display comprising a rear chassis member, a
bezel member, a reflecting sheet member, a reflecting plate member,
a reflecting plate supporting member and a box member, wherein at
least one of said rear chassis member, said bezel member, said
reflecting sheet member, said reflecting plate member, said
reflecting plate supporting member and said box member is
constituted by an Al--Mg--Si series alloy plate manufactured by a
method, the method comprising the steps of: preparing Al--Mg--Si
series alloy ingot consisting essentially of Si: 0.2 to 0.8 wt %,
Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt % or less, Cu: 0.20 wt % or less
and the balance being aluminum and inevitable impurities;
homogenizing said alloy ingot; subjecting said alloy ingot to rough
hot rolling to obtain a roughly hot rolled plate; subjecting said
roughly hot rolled plate to finish hot rolling to obtain a finished
hot rolled plate; and subjecting said finished hot rolled plate to
cold rolling, wherein one of plural passes performed at said rough
hot rolling is controlled such that material temperature
immediately before said one of plural passes is from 350 to
440.degree. C., cooling rate during said one of plural passes is
50.degree. C./min or more, material temperature immediately after
said one of plural passes is from 250 to 340.degree. C. and plate
thickness immediately after said one of plural passes is 10 mm or
more but not larger than 15 mm, wherein said cold rolling is
controlled such that rolling reduction is 30% or more, and wherein
said cold rolled plate is subjected to final aging at a temperature
of 180.degree. C. or below, or is not subjected to final aging.
31. A plasma display comprising a rear chassis member, a box member
and an exterior member, wherein at least one of said rear chassis
member, said box member and said exterior member is constituted by
an Al--Mg--Si series alloy plate manufactured by a method, the
method comprising the steps of: preparing Al--Mg--Si series alloy
ingot consisting essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9
wt %, Fe: 0.5 wt % or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or
less and the balance being aluminum and inevitable impurities;
homogenizing said alloy ingot; subjecting said alloy ingot to rough
hot rolling to obtain a roughly hot rolled plate; subjecting said
roughly hot rolled plate to finish hot rolling to obtain a finished
hot rolled plate; and subjecting said finished hot rolled plate to
cold rolling, wherein one of plural passes performed at said rough
hot rolling is controlled such that material temperature
immediately before said one of plural passes is from 350 to
440.degree. C., cooling rate during said one of plural passes is
50.degree. C./min or more, material temperature immediately after
said one of plural passes is from 250 to 340.degree. C. and plate
thickness immediately after said one of plural passes is not larger
than 15 mm, wherein said cold rolling is controlled such that
rolling reduction is 30% or more, and wherein said cold rolled
plate is subjected to final aging at a temperature of 180.degree.
C. or below, or is not subjected to final aging.
32. A liquid crystal display comprising a rear chassis member, a
bezel member, a reflecting sheet member, a reflecting plate member,
a reflecting plate supporting member and a box member, wherein at
least one of said rear chassis member, said bezel member, said
reflecting sheet member, said reflecting plate member, said
reflecting plate supporting member and said box member is
constituted by an Al--Mg--Si series alloy plate manufactured by a
method, the method comprising the steps of: preparing Al--Mg--Si
series alloy ingot consisting essentially of Si: 0.2 to 0.8 wt %,
Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt % or less, Cu: 0.20 wt % or less,
Zn: 0.5 wt % or less and the balance being aluminum and inevitable
impurities; homogenizing said alloy ingot; subjecting said alloy
ingot to rough hot rolling to obtain a roughly hot rolled plate;
subjecting said roughly hot rolled plate to finish hot rolling to
obtain a finished hot rolled plate; and subjecting said finished
hot rolled plate to cold rolling, wherein one of plural passes
performed at said rough hot rolling is controlled such that
material temperature immediately before said one of plural passes
is from 350 to 440.degree. C., cooling rate during said one of
plural passes is 50.degree. C./min or more, material temperature
immediately after said one of plural passes is from 250 to
340.degree. C. and plate thickness immediately after said one of
plural passes is not larger than 15 mm, wherein said cold rolling
is controlled such that rolling reduction is 30% or more, and
wherein said cold rolled plate is subjected to final aging at a
temperature of 180.degree. C. or below, or is not subjected to
final aging.
Description
[0001] This is a continuation-in-part of commonly assigned
co-pending application Ser. No. 09/818,070, filed on Mar. 27,
2001.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an Al--Mg--Si series alloy plate
excellent in thermal conductivity and strength, and also relates to
a method of manufacturing the aforementioned Al--Mg--Si series
alloy plate.
[0004] 2. Description of Related Art
[0005] Generally, Japanese Industrial Standards (hereinafter
referred to as "JIS") A5052 aluminum alloy is used as high strength
aluminum materials for heat exchanger parts, metallic base printed
circuit boards, cutting members, etc. However, JIS A5052 aluminum
alloy is inferior in thermal conductivity by 30% or more as
compared with pure aluminum. On the other hand, pure aluminum
having high excellent thermal conductivity is extremely low in
strength and inferior to JIS A5052 aluminum alloy in cutting
processability. This pure aluminum requires removal of burrs after
cutting processing, resulting in poor finished surface
appearance.
[0006] Furthermore, Al--Mg--Si series alloy is also used as
aluminum material of high strength in which minute Mg.sub.2Si
particles are precipitated uniformly to improve the strength. The
fine Mg.sub.2Si precipitation can be obtained by heat treatment,
which improves strength and recovers toughness by hardening and
annealing the alloy after cold rolling. Heating the alloy in
general rolling process does not cause uniform and fine Mg.sub.2Si
precipitation, but merely causes independent precipitation of Mg
and Si, resulting in insufficient strength improvement.
[0007] Thus, under the present circumstances, it is additionally
required to perform heat treatment after cold rolling, resulting in
an increased step, which causes an increased manufacturing cost.
Furthermore, in cases where a thin plate having a thickness of 0.1
mm or the like is manufactured by heat treatment type alloy such as
Al--Mg--Si series alloy, since it was common to subject the alloy
plate of 1 mm thickness or less to solution treatment in a
continuous annealing furnace, it was difficult to increase the cold
working rate. As a result, it was difficult to obtain high
strength.
[0008] Japanese Unexamined Laid-open Patent Publication No.
H6-272001 discloses a method of manufacturing an Al--Mg--Si series
alloy plate in which hot rolling conditions are specified. This
technique intends to restrain big and rough precipitation from
being generated during hot rolling in order to perform short-time
solution treatment after cold rolling, and does not intend to
promote fine Mg.sub.2Si precipitation during the rolling
process.
SUMMARY OF THE INVENTION
[0009] It is an object of the present invention to provide a method
of manufacturing aluminum alloy with outstanding thermal
conductivity and strength in fewer steps.
[0010] A first method of manufacturing an Al--Mg--Si series alloy
plate according to the present invention has the following
structural features (1) to (10) and the second method of
manufacturing an Al--Mg--Si series alloy plate has the following
structural features (11) to (20).
[0011] (1) A method of manufacturing an Al--Mg--Si series alloy
plate excellent in thermal conductivity and strength, the method
comprising the steps of:
[0012] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less and the balance being aluminum and
inevitable impurities;
[0013] homogenizing the alloy ingot;
[0014] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0015] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0016] subjecting the finished hot rolled plate to cold
rolling,
[0017] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440', cooling rate
during the one of plural passes is 50.degree. C./min or more,
material temperature immediately after the one of plural passes is
from 250 to 340.degree. C. and plate thickness immediately after
the one of plural passes is 10 mm or more but not larger than 15
mm,
[0018] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0019] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0020] (2) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein Si content
of the Al--Mg--Si series alloy ingot is from 0.32 to 0.60 wt %.
[0021] (3) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein Mg content
of the Al--Mg--Si series alloy ingot is from 0.35 to 0.55 wt %.
[0022] (4) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein the
material temperature immediately before the one of plural passes is
from 380 to 420.degree. C.
[0023] (5) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein the plate
thickness immediately after the one of plural passes is 12 mm or
less.
[0024] (6) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein the
material temperature immediately before the one of plural passes is
from 380 to 420.degree. C., and wherein the plate thickness
immediately after the one of plural passes is 12 mm or less.
[0025] (7) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein the
rolling reduction of the cold rolling is 50% or more. (8) The
method of manufacturing an Al--Mg--Si series alloy plate as recited
in the aforementioned Item (1), wherein the material temperature
immediately before the one of plural passes is from 380 to
420.degree. C., and wherein the rolling reduction of the cold
rolling is 50% or more.
[0026] (9) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein the plate
thickness immediately after the one of plural passes is 12 mm or
less, and wherein the rolling reduction of the cold rolling is 50%
or more.
[0027] (10) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (1), wherein the
material temperature immediately before the one of plural passes is
from 380 to 420.degree. C., wherein the plate thickness immediately
after the one of the plural passes is 12 mm or less, and wherein
the rolling reduction of the cold rolling is 50% or more.
[0028] (11) A method of manufacturing an Al--Mg--Si series alloy
plate excellent in thermal conductivity and strength, the method
comprising the steps of:
[0029] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or less and the
balance being aluminum and inevitable impurities;
[0030] homogenizing the alloy ingot;
[0031] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0032] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0033] subjecting the finished hot rolled plate to cold
rolling,
[0034] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440.degree. C.,
cooling rate during the one of plural passes is 50.degree. C./min
or more, material temperature immediately after the one of plural
passes is from 250 to 340.degree. C. and plate thickness
immediately after the one of plural passes is 15 mm or less,
[0035] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0036] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0037] (12) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein Si
content of the Al--Mg--Si series alloy ingot is from 0.32 to 0.60
wt %.
[0038] (13) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein Mg
content of the Al--Mg--Si series alloy ingot is from 0.35 to 0.55
wt %.
[0039] (14) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein the
material temperature immediately before the one of plural passes is
from 380 to 420.degree. C.
[0040] (15) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein the plate
thickness immediately after the one of plural passes is 12 mm or
less.
[0041] (16) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein the
material temperature immediately before the one of plural passes is
from 380 to 420.degree. C., and wherein the plate thickness
immediately after the one of plural passes is 12 mm or less.
[0042] (17) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein the
rolling reduction of the cold rolling is 50% or more.
[0043] (18) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein the
material temperature immediately before the one of plural passes is
from 380 to 420.degree. C., and wherein the rolling reduction of
the cold rolling is 50% or more.
[0044] (19) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein the plate
thickness immediately after the one of plural passes is 12 mm or
less, and wherein the rolling reduction of the cold rolling is 50%
or more.
[0045] (20) The method of manufacturing an Al--Mg--Si series alloy
plate as recited in the aforementioned Item (11), wherein the
material temperature immediately before the one of plural passes is
from 380 to 420.degree. C., wherein the plate thickness immediately
after the one of the plural passes is 12 mm or less, and wherein
the rolling reduction of the cold rolling is 50% or more.
[0046] A first Al--Mg--Si series alloy plate excellent in thermal
conductivity and strength according to the present invention is an
alloy plate manufactured by the aforementioned method (1) to (10)
and has the following structural features (21) to (24). A second
Al--Mg--Si series alloy plate excellent in thermal conductivity and
strength according to the present invention is an alloy plate
manufactured by the aforementioned method (11) to (20) and has the
following structural features (25) to (28).
[0047] (21) An Al--Mg--Si series alloy plate excellent in thermal
conductivity and strength manufactured by a method, the method
comprising the steps of:
[0048] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less and the balance being aluminum and
inevitable impurities;
[0049] homogenizing the alloy ingot;
[0050] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0051] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0052] subjecting the finished hot rolled plate to cold
rolling,
[0053] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440.degree. C.,
cooling rate during the one of plural passes is 50.degree. C./min
or more, material temperature immediately after the one of plural
passes is from 250 to 340.degree. C. and plate thickness
immediately after the one of plural passes is 10 mm or more but not
larger than 15 mm,
[0054] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0055] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0056] (22) The Al--Mg--Si series alloy plate as recited in the
aforementioned Item (21), wherein the 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.
[0057] (23) The Al--Mg--Si series alloy plate as recited in the
aforementioned Item (22), wherein the 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.
[0058] (24) The Al--Mg--Si series alloy plate as recited in the
aforementioned Item (22), wherein the 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.
[0059] (25) An Al--Mg--Si series alloy plate excellent in thermal
conductivity and strength manufactured by a method, the method
comprising the steps of:
[0060] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or less and the
balance being aluminum and inevitable impurities;
[0061] homogenizing the alloy ingot;
[0062] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0063] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0064] subjecting the finished hot rolled plate to cold
rolling,
[0065] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440.degree. C.,
cooling rate during the one of plural passes is 50.degree. C./min
or more, material temperature immediately after the one of plural
passes is from 250 to 340.degree. C. and plate thickness
immediately after the one of plural passes is 15 mm or less,
[0066] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0067] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0068] (26) The Al--Mg--Si series alloy plate as recited in the
aforementioned Item (25), wherein the 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.
[0069] (27) The Al--Mg--Si series alloy plate as recited in the
aforementioned Item (26), wherein the 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.
[0070] (28) The Al--Mg--Si series alloy plate as recited in the
aforementioned Item (26), wherein the 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.
[0071] The first plasma display and liquid crystal display utilize
the Al alloy plate as defined by the aforementioned Item (21) as
the constitutional materials, and has the structural features as
defined by the following Items (29) and
[0072] (30). The second plasma display and liquid crystal display
utilize the Al alloy plate as defined by the aforementioned Item
(25) as the constitutional materials, and has the structural
features as defined by the following Items (31) and (32).
[0073] (29) A plasma display comprising a rear chassis member, a
box member and an exterior member, wherein at least one of the rear
chassis member, the box member and the exterior member is
constituted by an Al--Mg--Si series alloy plate manufactured by a
method, the method comprising the steps of:
[0074] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less and the balance being aluminum and
inevitable impurities;
[0075] homogenizing the alloy ingot;
[0076] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0077] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0078] subjecting the finished hot rolled plate to cold
rolling,
[0079] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440.degree. C.,
cooling rate during the one of plural passes is 50.degree. C./min
or more, material temperature immediately after the one of plural
passes is from 250 to 340.degree. C. and plate thickness
immediately after the one of plural passes is 10 mm or more but not
larger than 15 mm,
[0080] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0081] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0082] (30) A liquid crystal display comprising a rear chassis
member, a bezel member, a reflecting sheet member, a reflecting
plate member, a reflecting plate supporting member and a box
member, wherein at least one of the rear chassis member, the bezel
member, the reflecting sheet member, the reflecting plate member,
the reflecting plate supporting member and the box member is
constituted by an Al--Mg--Si series alloy plate manufactured by a
method, the method comprising the steps of:
[0083] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less and the balance being aluminum and
inevitable impurities;
[0084] homogenizing the alloy ingot;
[0085] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0086] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0087] subjecting the finished hot rolled plate to cold
rolling,
[0088] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440.degree. C.,
cooling rate during the one of plural passes is 50.degree. C./min
or more, material temperature immediately after the one of plural
passes is from 250 to 340.degree. C. and plate thickness
immediately after the one of plural passes is 10 mm or more but not
larger than 15 mm,
[0089] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0090] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0091] (31) A plasma display comprising a rear chassis member, a
box member and an exterior member, wherein at least one of the rear
chassis member, the box member and the exterior member is
constituted by an Al--Mg--Si series alloy plate manufactured by a
method, the method comprising the steps of:
[0092] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or less and the
balance being aluminum and inevitable impurities;
[0093] homogenizing the alloy ingot;
[0094] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0095] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0096] subjecting the finished hot rolled plate to cold
rolling,
[0097] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440.degree. C.,
cooling rate during the one of plural passes is 50.degree. C./min
or more, material temperature immediately after the one of plural
passes is from 250 to 340.degree. C. and plate thickness
immediately after the one of plural passes is not larger than 15
mm,
[0098] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0099] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0100] (32) A liquid crystal display comprising a rear chassis
member, a bezel member, a reflecting sheet member, a reflecting
plate member, a reflecting plate supporting member and a box
member, wherein at least one of the rear chassis member, the bezel
member, the reflecting sheet member, the reflecting plate member,
the reflecting plate supporting member and the box member is
constituted by an Al--Mg--Si series alloy plate manufactured by a
method, the method comprising the steps of:
[0101] preparing Al--Mg--Si series alloy ingot consisting
essentially of Si: 0.2 to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt
% or less, Cu: 0.20 wt % or less, Zn: 0.5 wt % or less and the
balance being aluminum and inevitable impurities;
[0102] homogenizing the alloy ingot;
[0103] subjecting the alloy ingot to rough hot rolling to obtain a
roughly hot rolled plate;
[0104] subjecting the roughly hot rolled plate to finish hot
rolling to obtain a finished hot rolled plate; and
[0105] subjecting the finished hot rolled plate to cold
rolling,
[0106] wherein one of plural passes performed at the rough hot
rolling is controlled such that material temperature immediately
before the one of plural passes is from 350 to 440.degree. C.,
cooling rate during the one of plural passes is 50.degree. C./min
or more, material temperature immediately after the one of plural
passes is from 250 to 340.degree. C. and plate thickness
immediately after the one of plural passes is not larger than 15
mm,
[0107] wherein the cold rolling is controlled such that rolling
reduction is 30% or more, and
[0108] wherein the cold rolled plate is subjected to final aging at
a temperature of 180.degree. C. or below, or is not subjected to
final aging.
[0109] Methods according to the present invention are roughly
classified into two methods which are different in compositions of
the Al--Mg--Si series alloy and a part of rolling conditions.
[0110] The targeted Al--Mg--Si alloy in the first method
(hereinafter referred to as "first alloy") is an alloy containing
Mg, Si, Fe and Cu. The targeted Al--Mg--Si alloy in the second
method (hereinafter referred to as "second alloy") is an alloy
containing Mg, Si, Fe, Cu and Zn.
[0111] The significance and reasons for the limitation of each
element of the Al--Mg--Si alloy compositions are explained as
follows.
[0112] Mg, Si, Fe and Cu are elements commonly contained in the
first and second alloys.
[0113] Mg and Si are essential elements for giving strength to the
alloy. If Mg content is less than 0.3 wt % and/or Si content is
less than 0.2 wt %, sufficient strength cannot be obtained. On the
other hand, if Mg content exceeds 0.9 wt % and/or Si content
exceeds 0.8 wt %, the rolling load in the hot rolling increases,
which causes a deterioration of productivity and necessitates
trimming of the rolled plate before the finish rolling because of
the generated large cracks. The desirable lower limit of Mg content
is 0.35 wt %, and the desirable upper limit thereof is 0.55 wt %.
On the other hand, the desirable lower limit of Si content is 0.32
wt %, and the desirable upper limit thereof is 0.60 wt %.
[0114] Too much Fe and Cu causes a deterioration of corrosion
resistance, resulting in an alloy plate of no practical use.
Therefore, it is necessary to regulate the content of Fe and Cu
such that Fe content is 0.5 wt % or less and Cu content is 0.20 wt
% or less. The dpreferable Fe content is 0.25 wt % or less, and the
preferable Cu content is 0.10 wt % or less.
[0115] The alloy compositions falling within the aforementioned
range causes outstanding thermal conductivity equivalent to pure
aluminum.
[0116] Zn is an element contained only in the second alloy. Adding
a small amount of Zn such as 0.5 wt % or less does not spoil the
excellent thermal conductivity, strength and electric conductivity
that are important features of the alloy plate according to the
present invention. Accordingly, the present invention makes it
possible to reuse the Zn containing alloy which is generally
difficult to use as recycling materials. This enlarges the
application range of such Zn containing alloy recycling materials,
which in turn contributes environmental conservations. Furthermore,
too much Zn causes a deterioration of corrosion resistance,
resulting in a lacking of practicality. However, if it is
controlled such that Zn content is 0.5 wt % or less, practical
corrosion resistance can be assured. The preferable Zn content is
0.25 wt % or less.
[0117] In the aforementioned two methods according to the present
invention, fine Mg.sub.2Si particles can be precipitated uniformly
by applying rolling under the prescribed conditions after the
homogenization treatment. As a result, effects equivalent to
effects obtained by solution treatment and quenching can be
obtained.
[0118] The conditions of the homogenization treatment are not
specifically limited. It is preferable to perform the
homogenization treatment for 2 hours or more at 500.degree. C. or
above in accordance with a conventional method.
[0119] In the rough hot rolling, effects equivalent to effects
obtained by quenching can be obtained by the temperature reduction
while rough hot rolling under the predetermined temperature
conditions in any one of plural passes performed at the rough hot
rolling. Therefore, the material temperature immediately before the
one of plural passes is required to fall within the range of from
350 to 440.degree. C. which can retain the dissolved state of Mg
and Si like in solution treatment. If the material temperature is
below 350.degree. C., Mg.sub.2Si becomes big and rough
precipitation at this time, and thus the subsequent quenching
effect cannot be obtained. Furthermore, since the material
temperature is low, the rolling processability at the subsequent
rough hot rolling passes deteriorates remarkably, the material
temperature immediately after the one of plural passes becomes too
low, resulting in a deterioration of the surface quality. On the
other hand, if the material temperature exceeds 440.degree. C., the
material temperature will not drop enough immediately after the one
of plural passes, causing insufficient quenching effects. The
preferable lower limit of the material temperature immediately
before the one of plural passes is 380.degree. C., and the
preferable upper limit is 420.degree. C. Furthermore, in order to
obtain the quenching effects, it is required to control such that
the cooling rate during the one of plural passes is 50.degree.
C./min and that the material temperature immediately after the one
of plurals passes falls within the range of from 250 to 340.degree.
C. In order to control the material temperature immediately after
the one of plural passes so as to fall within the aforementioned
range, forced cooling such as high-pressure shower water cooling
may be performed immediately after the rough hot rolling.
Furthermore, it is preferable that the rough hot rolling velocity
is 50 m/min or higher.
[0120] Furthermore, in order to obtain cooling effects equivalent
to quenching between the one of plural passes and the subsequent
pass, it is necessary to control the plate thickness immediately
after the one of plural passes. In the first alloy, it is necessary
to control the plate thickness immediately after the one of plural
passes so as to be not smaller than 10 mm but not larger than 15
mm. In the second alloy, it is necessary to control the plate
thickness immediately after the one of plural passes so as to be
not larger than 15 mm. In either case, if the thickness exceeds 15
mm, it is difficult to cool the plate to a temperature sufficient
for quenching even if an additional water-cooling process is
performed. The preferable plate thickness is 12 mm or less. The
rolling conditions for the first alloy and those for the second
alloy are different only in the aforementioned plate thickness
immediately after the one of plural passes, and the other
conditions are the same.
[0121] Generally, although the aforementioned rough hot rolling
will be performed 10 times (passes) or more, the aforementioned
rough hot rolling pass under the aforementioned conditions in order
to obtain the quenching effects can be performed at any one of
plural rough hot rolling passes. However, since it is required to
make the plate thickness immediately after the one of plural passes
15 mm or less, the aforementioned one of passes is usually
performed at the last rough hot rolling pass or at a pass
immediately before the last rough hot rolling pass. However, in
cases where the aforementioned rough hot rolling is performed at
any one of plural passes other than the last rough hot rolling
pass, it is required to perform the rough hot rolling pass
subsequent to the one of plural passes at the material temperature
of from 250 to 340.degree. C. If the material temperature is below
250.degree. C., the load of rolling becomes larger. As a result, it
becomes hard to perform the rough hot rolling because of the large
load and the surface quality changes such as surface corrosion due
to the reaction of aluminum and moisture.
[0122] The conditions of the final hot rolling to be performed
after the rough hot rolling passes, such as the result temperature
and/or the rolling velocity, are not specifically limited because
solution treatment and quench treatment have been already performed
by the preceding rough rolling. Accordingly, the final hot rolling
can be performed depending on the plate thickness by a conventional
method.
[0123] In the cold rolling, in order to obtain a predetermined
strength by work hardening, it is necessary to control such that
the rolling reduction is 30% or more. When the rolling reduction is
30% or more, the strength of 200 N/mm.sup.2 or more equal to the
strength of A5052 alloy (JIS(Japanese Industrial Standards) H4000)
can be obtained. A desirable rolling reduction is 50% or more.
[0124] Furthermore, if necessary, the final aging of the cold
rolled alloy plate is performed at 180.degree. C. or below. By
performing the heat treatment at such a low temperature, the age
hardening of the alloy plate will be executed to further increase
the strength and the elongation. Furthermore, mechanical
characteristics will also be stabilized. The preferable thermal
treatment temperature is from 130 to 150.degree. C.
[0125] Since the targeted Al--Mg--Si series alloy to be
manufactured in accordance with the first manufacturing method
according to the present invention consists essentially of Si: 0.2
to 0.8 wt %, Mg: 0.3 to 0.9 wt %, Fe: 0.5 wt % or less, Cu: 0.20 wt
% or less and the balance being aluminum and inevitable impurities,
and the targeted Al--Mg--Si series alloy to be manufactured in
accordance with the second manufacturing method according to the
present invention consists essentially of Si: 0.2 to 0.8 wt %, Mg:
0.3 to 0.9 wt %, Fe: 0.5 wt % or less, Cu: 0.20 wt % or less, Zn:
0.5 wt % or less and the balance being aluminum and inevitable
impurities, either alloy is excellent in thermal conductivity.
[0126] The method of manufacturing an Al--Mg--Si series alloy plate
according to the present invention includes the steps of:
homogenizing the Al--Mg--Si series alloy ingot; subjecting the
alloy to rough hot rolling to obtain a roughly hot rolled plate;
subjecting the roughly hot rolled plate to finish hot rolling to
obtain a finished hot rolled plate; and subjecting the finished hot
rolled plate to cold rolling, wherein one of plural passes
performed at the rough hot rolling is controlled such that material
temperature immediately before the one of plural passes is from 350
to 440.degree. C., cooling rate during the one of plural passes is
50.degree. C./min or more, material temperature immediately after
the one of plural passes is from 250 to 340.degree. C. and plate
thickness immediately after the one of plural passes is larger than
10 mm but not larger than 15 mm in the first method, not larger
than 15 mm in the second method, and wherein the cold rolling is
controlled such that rolling reduction is 30% or more. Accordingly,
during the rough hot rolling, it is possible to obtain effects
equivalent to the effects obtained by solution treatment and quench
treatment. Furthermore, still higher strength can be obtained by
the cold rolling at the higher rolling reduction. Therefore,
without performing heat treating at another process other than
rolling process, an alloy plate having high thermal conductivity
and high strength can be manufactured, and a large cost reduction
can be attained. Furthermore, if the cold rolled plate is further
subjected to final aging at a temperature of 180.degree. C. or
below, the strength and elongation can be further improved and the
mechanical characteristics can be stabilized. Furthermore, since
the Al--Mg--Si series alloy plate manufactured by the method
explained above has good cutting processability, when cutting of
this alloy plate is performed, post processing, such as deburring,
become unnecessary and a cost reduction can also be attained.
Furthermore, since the thermal conductivity of Al--Mg--Si series
alloy is good, the alloy plate having high thermal conductivity and
high strength can be manufactured by the aforementioned either
method.
[0127] Furthermore, in the aforementioned two kinds of Al--Mg--Si
series alloy ingot compositions, in cases where Si content is 0.32
to 0.60 wt % and/or Mg content is 0.35 to 0.55 wt %, the obtained
alloy plate is excellent especially in strength.
[0128] Furthermore, in cases where the material temperature
immediately before the one of plural passes is 380 to 420.degree.
C., sufficient quenching effects can be obtained while maintaining
the rolling workability.
[0129] Furthermore, in cases where the plate thickness immediately
after the one of plural passes is 12 mm or less, the plate can be
fully cooled between the one of plural passes and a pass subsequent
thereto. Thus, sufficient quenching effects can be obtained.
[0130] Furthermore, in cases where the rolling reduction at the
cold rolling is 50% or more, the strength improvement effect due to
work hardening will be remarkable.
[0131] The Al--Mg--Si series alloy plates manufactured by the
aforementioned two methods according to the present invention are
excellent in various characteristics mentioned above. Therefore,
the alloy plates can be subjected to various forming processing.
For example, the alloy plates can be preferably used as heat
releasing member materials, current carrying member materials, case
materials, reflecting plates or its supporting members. The
aforementioned heat releasing member includes not only a member for
releasing heat as its original purpose, e.g., a heat exchanger and
a heat sink, but also a member required to have heat release
performance other than its main purpose, e.g., a chassis or a metal
base print circuit board of an electronic product such as a PDP, an
LCD or a personal computer to which a built-in heat releasing or a
heat releasing member is attached. As for the current carrying
member, a bus bar member, various battery terminals members,
capacitor terminal members for use in fuel cell vehicles or hybrid
cars, terminal members of various electrical equipments and
terminal members of machine appliance can be exemplified. As for
the case materials, battery cases or boxes for cellular phones,
PDA's, etc. and boxes for various electric equipments can be
exemplified. Since the alloy plate according to the present
invention is excellent in strength and cutting processability, even
a thin alloy plate can be used for a casing, and it is possible to
provide a casing having sufficient strength, which is small in size
and light in weight. As for the reflecting plate, a light
reflecting plate for a liquid crystal beneath type backlight, a
light reflecting plate for a liquid crystal edge-light type unit
and a reflecting plate for an electric decorative display can be
exemplified. The alloy plate may also be used as a supporting
member for the aforementioned reflecting plate made of material
other than aluminum. For example, a reflecting plate in which a
porous resin sheet made of foamed resin composition containing
inorganic filler such as olefin series polymer, barium sulfate,
calcium carbonate or titanium oxide is laminated on the Al--Mg--Si
series alloy plate of the present invention can be exemplified. The
porous resin sheet is laminated on a supporting member by
lamination processing or via an adhesive tape. Furthermore, as a
material of a reflecting plate, white paint is sometimes used. In
this case, a supporting member on which white paint is applied can
be used as a reflecting plate. Furthermore, as a member to which
heat releasing, strength and lightness are required, a keyboard
substrate for use in computers, especially note-type computers
which should be extremely small in size and light in weight, a heat
spreader plate and a box can be exemplified. Furthermore, it can be
used as various strengthening members.
[0132] Concretely, the Al--Mg--Si series alloy plate can be used as
a material for a plasma display related material such as a plasma
display rear surface chassis member, a plasma display box member
and a plasma display exterior member, or a liquid crystal display
material such as 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. The
aforementioned plasma display rear chassis member can be also
served as a heat releasing plate.
[0133] Furthermore, in a plasma display, it becomes possible to
decrease the size and weight by utilizing any one of the
aforementioned two kinds of Al--Mg--Si series alloy plates as an Al
alloy plate constituting at least any one of rear surface chassis
member, plasma display box member and plasma display exterior
member. In the same way, in a liquid crystal display, it becomes
possible to decrease the size and weight by utilizing any one of
the aforementioned two kinds of Al--Mg--Si series alloy plates as
an Al alloy plate constituting at least any one of rear chassis
member, bezel member, reflecting sheet member, reflecting sheet,
reflecting sheet supporting member and box material.
EXAMPLE
[0134] Each of the alloy continuous casting slabs having
compositions shown in Tables 1 and 2 was subjected to
homogenization treatment of 580.degree. C..times.10 hours after
surface cutting, and then subjected to rough hot rolling, final hot
rolling and cold rolling to obtain an alloy plate. The rolling
conditions were controlled at the final rough hot rolling pass. The
material temperature immediately before the final rough hot rolling
pass was set to the temperature shown in each Table, the final
rough hot rolling velocity was set to 80 m/min, and the thickness
immediately after the final rough hot rolling pass was set as shown
in each Table. The cooling rate during the pass was set as shown in
each Table. Then, the material after the rough hot rolling was
subjected to further finish hot rolling to be rolled into a coil.
Next, the rolled material was subjected to cold rolling at the
rolling reduction shown in each Table. After the cold rolling, the
examples Nos. 2, 4, 11, 13, 15, 16, 22, 24, 31, 33, 35, 36 and the
comparative examples Nos. 7, 9, 13 and 15 were further subjected to
the final annealing under the conditions shown in each Table. As
for the comparative examples Nos. 1, 2 and 3, A1100P-H24 material,
A5052P-H38 material, and A5052P-H34 material were manufactured by
usual processing, respectively.
[0135] Tensile strength and thermal conductivity of each obtained
alloy plate were measured, and its cutting ability was also
evaluated in accordance with milling processing. The tensile
strength was measured by the conventional method with JIS No.5
specimen, and the thermal conductivity was measured with a laser
flash method at 25.degree. C. Furthermore, the cutting
processability was relatively evaluated on the basis shown below.
However, as for the examples Nos. 10, 11, 30 and 31, since the
final plate thickness was 0.1 mm and this kind of thin plate or
foil will be usually used without being subjected to cutting
process, the cutting processability were not evaluated.
1TABLE 1 (Corresponding to claims 1 to 10: non Zn, plate thickness:
larger than 10 mm but not larger than 15 mm) Hot rough rolling
final pass Thick- Temp. Temp. ness before after after Cold Final
Thermal Composition (wt %) the the the Cooling rolling aging
Tensile conduc- Cutting Alloy Balance: Al and Impurities pass pass
pass rate reduction (.degree. C. .times. Strength tivity process-
No. Si Mg Fe Cu Zn (.degree. C.) (.degree. C.) (mm) (.degree.
C./min) rate (%) hr) (N/mm.sup.2) (W/mK) ablity Remarks Ex- ample 1
0.5 0.5 0.15 0.05 -- 395 277 11 125 60 -- 230 203 .largecircle. 2
0.5 0.5 0.15 0.05 -- 395 277 11 125 60 150 .times. 5 258 220
.largecircle. 3 0.5 0.5 0.15 0.05 -- 395 282 11 123 85 -- 263 195
.largecircle. 4 0.5 0.5 0.15 0.05 -- 395 282 11 123 85 140 .times.
5 286 216 .largecircle. 5 0.5 0.5 0.15 0.05 -- 436 317 11 150 85 --
238 212 .largecircle. 6 0.7 0.4 0.18 0.07 -- 400 332 12 90 60 --
240 207 .largecircle. 7 0.3 0.8 0.13 0.05 -- 396 325 12 60 65 --
240 200 .largecircle. 8 0.3 0.4 0.13 0.05 -- 394 320 12 63 70 --
237 220 .largecircle. 9 0.4 0.7 0.20 0.15 -- 392 288 12 88 85 --
238 196 .largecircle. 10 0.4 0.7 0.13 0.05 -- 400 330 12 140 98 --
390 197 -- Product plate thickness 0.1 mm 11 0.4 0.7 0.13 0.05 --
400 330 12 140 98 130 .times. 5 395 198 -- Product plate thickness
0.1 mm 12 0.5 0.5 0.24 0.05 -- 418 330 15 150 70 -- 290 197
.largecircle. 13 0.5 0.5 0.24 0.05 -- 418 330 14 150 70 130 .times.
5 288 196 .largecircle. 14 0.5 0.5 0.22 0.07 -- 415 335 14 150 70
-- 288 195 .largecircle. 15 0.5 0.5 0.4 0.05 -- 410 334 12 150 65
130 .times. 5 275 192 .largecircle. 16 0.5 0.5 0.4 0.10 -- 410 333
12 150 65 130 .times. 5 280 193 .largecircle. Com- para- tive Ex-
ample 1 0.12 0.01 0.57 0.12 -- 395 290 7 *1 75 -- 140 218 X
A1100P-H24 2 0.07 2.51 0.25 0.02 -- 395 292 7 *1 70 -- 295 138
.largecircle. A5052P-H38 3 0.07 2.51 0.25 0.02 -- 396 288 7 *1 70
-- 255 142 .largecircle. A5052P-H34 4 0.1 0.2 0.10 0.05 -- 394 282
7 80 85 -- 170 214 .DELTA. 5 0.9 0.5 0.14 0.14 -- 450 380 16 160 70
-- 185 180 .DELTA. 6 0.5 1.0 0.11 0.08 -- 450 380 16 160 70 -- 273
159 .largecircle. 7 0.5 1.0 0.11 0.06 -- 450 380 16 160 70 150
.times. 5 278 163 .largecircle. 8 0.5 0.5 0.15 0.05 -- 450 362 7 80
60 -- 178 210 .DELTA. 9 0.5 0.5 0.15 0.05 -- 454 366 7 80 60 150
.times. 5 171 214 .DELTA. *1 denotes: no forced cooling
.largecircle.: Outstanding (no burrs) .DELTA.: Good (some burrs) X:
Poor (many burrs).
[0136]
2TABLE 2 (Corresponding to claims 11 to 20: Zn: 0.5 or less, plate
thickness: not larger than 15 mm) Hot rough rolling final pass
Temp. Temp. before after Thickness Cold Thermal Composition (wt %)
the the after the Cooling rolling Final Tensile conduc- Cutting
Alloy Balance: Al and impurities pass pass pass rate reduction
aging Strength tivity process- No. Si Mg Fe Cu Zn (.degree. C.)
(.degree. C.) (mm) (.degree. C./min) rate (%) (.degree. C. .times.
hr) (N/mm.sup.2) (W/mK) ablity Remarks Ex- ample 21 0.5 0.5 0.15
0.05 0.21 395 277 7 80 60 -- 228 201 .largecircle. 22 0.5 0.5 0.15
0.05 0.21 395 277 7 80 60 150 .times. 5 255 218 .largecircle. 23
0.5 0.5 0.15 0.05 0.21 395 282 7 80 85 -- 258 193 .largecircle. 24
0.5 0.5 0.15 0.05 0.21 395 282 7 80 85 140 .times. 5 281 214
.largecircle. 25 0.5 0.5 0.15 0.05 0.5 436 317 7 80 85 -- 233 210
.largecircle. 26 0.7 0.4 0.18 0.07 0.21 400 332 10 120 60 -- 222
205 .largecircle. 27 0.3 0.8 0.13 0.05 0.21 396 325 10 120 65 --
247 197 .largecircle. 28 0.3 0.4 0.13 0.05 0.21 394 320 10 120 70
-- 255 218 .largecircle. 29 0.4 0.7 0.20 0.15 0.21 392 288 7 80 85
-- 292 193 .largecircle. 30 0.4 0.7 0.13 0.05 0.21 400 330 7 80 98
-- 368 193 -- Product plate thickness 0.1 mm 31 0.4 0.7 0.13 0.05
0.21 400 330 7 80 98 130 .times. 5 379 197 -- Product plate
thickness 0.1 mm 32 0.5 0.5 0.24 0.05 0.5 418 330 15 150 70 -- 227
192 .largecircle. 33 0.5 0.5 0.24 0.05 0.21 418 330 14 144 70 130
.times. 5 227 192 .largecircle. 34 0.5 0.5 0.22 0.07 0.21 415 335
14 144 70 -- 228 191 .largecircle. 35 0.5 0.5 0.4 0.05 0.21 410 334
12 130 65 130 .times. 5 231 192 .largecircle. 36 0.5 0.5 0.4 0.10
0.21 410 333 12 130 65 130 .times. 5 232 191 .largecircle. Com-
para- tive Ex- ample 11 0.9 0.5 0.14 0.14 0.21 450 380 16 160 70 --
185 180 .DELTA. 12 0.5 1.0 0.11 0.08 0.21 450 380 16 160 70 -- 273
159 .largecircle. 13 0.5 1.0 0.11 0.06 0.21 450 380 16 160 70 150
.times. 5 278 163 .largecircle. 14 0.5 0.5 0.15 0.05 0.21 450 362 7
80 60 -- 178 210 .DELTA. 15 0.5 0.5 0.15 0.05 0.21 454 366 7 80 60
150 .times. 5 171 214 .DELTA.
[0137] As will be apparent from the results shown in Tables 1 and
2, it was confirmed that the aluminum alloy plate with high thermal
conductivity equivalent to pure aluminum and high strength
equivalent to JIS A5052 alloy can be obtained by subjecting to
rough hot rolling and cold rolling under the conditions as defined
by the present invention. Furthermore, the cutting ability was also
good. The strength was also improved by further subjecting it to
the final aging.
[0138] The terms and expressions which have been employed herein
are used as terms of description and not of limitation, and there
is no intent, in the use of such terms and expression, of excluding
any of the equivalents of the features shown and described or
portions thereof, but it is recognized that various modifications
are possible which fall within the scope of the presently claimed
invention.
* * * * *