U.S. patent application number 10/589193 was filed with the patent office on 2007-11-29 for clad material, method for manufacturing said clad material, and apparatus for manufacturing said clad material.
This patent application is currently assigned to SHOWA DENKJO K.K.. Invention is credited to Kazuhiko Minami, Tomoaki Yamanoi.
Application Number | 20070272681 10/589193 |
Document ID | / |
Family ID | 37879300 |
Filed Date | 2007-11-29 |
United States Patent
Application |
20070272681 |
Kind Code |
A1 |
Yamanoi; Tomoaki ; et
al. |
November 29, 2007 |
Clad Material, Method for Manufacturing Said Clad Material, and
Apparatus for Manufacturing Said Clad Material
Abstract
A method for manufacturing a clad material in which a core
material is cast and skin materials are pressure-bonded thereon
aims to prevent deterioration of adhesiveness of the core material
and the skin materials while keeping sufficient cooling rate of the
core material, prevent thickness variation and/or breakage of the
skin materials during the manufacturing process, and keep the
surface property of the cooling rolls constant. The method for
manufacturing a clad material (11) includes the steps of
continuously supplying molten metal (M) into a gap between a pair
of cooling rollers (2a) (2b) to cast a core material, and cladding
skin materials (10a) (10b) on both surfaces of the core material
with hot rolling by continuously supplying the skin materials on
peripheral surfaces of the cooling rollers so that the skin
materials prevent direct contact between the cooling rollers and
the molten metal, wherein the skin materials are supplied so as to
come into contact with the peripheral surfaces of the cooling
rollers, and wherein a contact distance (L1) from a contact
starting point (P1) where the skin material begins to come into
contact with the cooling roller to a meeting point (P2) where the
skin material begins to come into contact with the molten metal is
set to 100 times or more of a thickness (t1) of the skin
material.
Inventors: |
Yamanoi; Tomoaki; (Tochigi,
JP) ; Minami; Kazuhiko; (Tochigi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
SHOWA DENKJO K.K.
13-9, Shiba Daimon 1-chome
Minato-ku
JP
105-8518
|
Family ID: |
37879300 |
Appl. No.: |
10/589193 |
Filed: |
February 10, 2005 |
PCT Filed: |
February 10, 2005 |
PCT NO: |
PCT/JP05/02532 |
371 Date: |
June 8, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60545530 |
Feb 19, 2004 |
|
|
|
Current U.S.
Class: |
219/615 |
Current CPC
Class: |
B21B 2001/383 20130101;
B22D 11/008 20130101; B21B 2003/001 20130101; B22D 11/0622
20130101; C22C 21/00 20130101; B32B 15/016 20130101; B21B 3/003
20130101 |
Class at
Publication: |
219/615 |
International
Class: |
B22D 11/06 20060101
B22D011/06; B21B 1/22 20060101 B21B001/22; C22C 21/00 20060101
C22C021/00; F28F 21/08 20060101 F28F021/08; B21B 11/00 20060101
B21B011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 12, 2004 |
JP |
2004-35186 |
Claims
1. A method for manufacturing a clad material, comprising the steps
of: continuously supplying molten metal into a gap between a pair
of cooling rollers to cast a core material; and cladding skin
materials on both surfaces of the core material with hot rolling by
continuously supplying the skin materials on peripheral surfaces of
the cooling rollers so that the skin materials prevent direct
contact between the cooling rollers and the molten metal, wherein
the skin materials are supplied so as to come into contact with the
peripheral surfaces of the cooling rollers, and wherein a contact
distance (L1) from a contact starting point (P1) where the skin
material begins to come into contact with the cooling roller to a
meeting point (P2) where the skin material begins to come into
contact with the molten metal is set to 100 times or more of a
thickness (t1) of the skin material.
2. The method for manufacturing a clad material as recited in claim
1, wherein the core material and the skin material are made of
aluminum or its alloy.
3. The method for manufacturing a clad material as recited in claim
1, wherein the thickness (t1) of the skin material is 20 to 400
.mu.m.
4. The method for manufacturing a clad material as recited in claim
2, wherein at least one of the skin materials is made of Al--Si
series alloy.
5. The method for manufacturing a clad material as recited in claim
4, wherein the Al--Si series alloy consists essentially of Si: 5 to
15 mass %, Fe: 0.05 to 0.6 mass %, Cu: 0.01 to 0.6 mass %, Mn: 0.01
to 0.8 mass %, Mg: 0.01 to 0.2 mass %, Ti: 0.01 to 0.2 mass %, and
the balance being Al and inevitable impurities.
6. The method for manufacturing a clad material as recited in claim
2, wherein at least one of the skin materials is made of Al--Zn
series alloy.
7. The method for manufacturing a clad material as recited in claim
6, wherein the Al--Zn series alloy consists essentially of Si: 0.05
to 0.6 mass %, Fe: 0.05 to 0.6 mass %, Cu: 0.01 to 0.6 mass %, Mn:
0.01 to 0.8 mass %, Mg: 0.01 to 0.2 mass %, Ti: 0.01 to 0.2 mass %,
Zn: 0.35 to 8.5 mass %, and the balance being Al and inevitable
impurities.
8. The method for manufacturing a clad material as recited in claim
1, wherein a thickness (t2) of the skin material after hot roll
cladding is 0.5 to 8 mm.
9. The method for manufacturing a clad material as recited in claim
2, wherein the molten metal to become the core material consists
essentially of Si: 0.05 to 1.5 mass %, Fe: 0.05 to 2 mass %, Cu:
0.05 to 0.8 mass %, Mn: 0.15 to 2.8 mass %, at least one of
elements selected from the group consisting of Cr: 0.03 to 0.7 mass
%, Mg: 0.01 to 0.2 mass %, Ti: 0.01 to 0.3 mass %, and Zn: 0.01 to
1.5 mass %, and the balance being Al and inevitable impurities.
10. The method for manufacturing a clad material as recited in
claim 9, wherein the molten metal further includes at least one of
elements selected from the group consisting of Zr: 0.15 to 1.5 mass
%, V: 0.03 to 1.5 mass %, and Sc: 0.02 to 0.5 mass %.
11. The method for manufacturing a clad material as recited in any
one of claims 1 to 10, wherein cold rolling is performed after the
hot roll cladding.
12. A clad material in which skin materials are clad on both
surfaces of a core material, wherein the clad material is
manufactured by the steps of continuously supplying molten metal
into a gap between a pair of cooling rollers to cast a core
material, and cladding skin materials on both surfaces of the core
material with hot rolling by continuously supplying the skin
materials on peripheral surfaces of the cooling rollers so that the
skin materials prevent direct contact between the cooling rollers
and the molten metal, wherein the skin materials are supplied so as
to come into contact with the peripheral surfaces of the cooling
rollers, and wherein a contact distance (L1) from a contact
starting point (P1) where the skin material begins to come into
contact with the cooling roller to a meeting point (P2) where the
skin material begins to come into contact with the molten metal is
set to 100 times or more of a thickness (t1) of the skin
material.
13. The clad material as recited in claim 12, wherein the clad
material is cold rolled after the hot roll cladding.
14. The clad material as recited in claim 12, wherein an average
spacing of a dendrite secondary arm spacing of the core material
formed by the heat roll cladding is 0.1 to 10 .mu.m
15. The clad material as recited in any one of claims 12 to 14,
wherein the clad material is heat exchanger component material.
16. An apparatus for manufacturing a clad material, comprising: a
pair of cooling rollers for continuously casting molten metal
passing through a gap formed between the cooling rollers; a molten
metal supplying portion for supplying the molten metal to become a
core material into the gap; and a skin material supplying portion
for supplying a skin material on a peripheral surface of the
cooling roller and making the skin material come into contact with
the peripheral surface of the cooling roller before the skin
material joins the molten metal, wherein the cooling rolls are
rotated while continuously supplying the molten metal and the skin
material to the cooling rolls to thereby continuously clad the skin
materials to both surfaces of the core material.
Description
[0001] Priority is claimed to Japanese Patent Application No.
2004-35186 filed on Feb. 12, 2004, and U.S. Provisional Application
No. 60/545,530 filed on Feb. 19, 2004, the disclosure of which are
incorporated by reference in their entireties.
CROSS REFERENCE TO RELATED APPLICATIONS
[0002] This application is an application filed under 35
U.S.C..sctn.111(a) claiming the benefit pursuant to 35
U.S.C..sctn.119(e)(1) of the filing date of U.S. Provisional
Application No. 60/545,530 filed on Feb. 19, 2004, pursuant to 35
U.S.C..sctn.111(b).
TECHNICAL FIELD
[0003] The present invention relates to a clad material with skin
materials laminated on both sides of a core material for giving,
for example, brazing performance and corrosion resistance,
especially, a clad material excellent in high-temperature strength,
a method for manufacturing such clad material, and an apparatus for
manufacturing such clad material.
BACKGROUND ART
[0004] The following description sets forth the inventor's
knowledge of related art and problems therein and should not be
construed as an admission of knowledge in the prior art.
[0005] In recent years, in accordance with reduction in size and
weight and improvement in performance of heat exchanges, the
materials thereof are required to be thin in thickness and high in
strength. Furthermore, for the purpose of decreasing environmental
burden, a request of alternatives for chlorofluorocarbon has
increased, and therefore a request of heat exchangers using
CO.sub.2 as refrigerant has increased. Examples of such heat
exchangers meeting the above demands include heat exchangers
represented by radiators and heater cores, which use water as a
principal component of refrigerant, heat exchangers represented by
condensers and evaporators, which use fleon gas as refrigerant, and
heat exchangers represented by gas coolers (evaporators), which use
CO.sub.2 as refrigerant.
[0006] As a component for use in these heat exchangers, a clad
material consisting of an aluminum alloy core and an aluminum alloy
skin material which gives brazing performance and corrosion
prevention performance to the surface of the core and having
sufficient strength even after brazing has been used. In a
generally employed method for manufacturing such clad material, a
pre-heated ingot is hot-rolled and then the surface thereof is
scraped to obtain a core material having a thickness of 250 mm to
400 mm. The core material and a skin material having a thickness of
10 to 100 mm are placed one on another and then temporarily fixed
with each other. Thereafter, the temporarily fixed members are
subjected to hot-rolling, cold-rolling and, if necessary,
intermediate annealing.
[0007] As a material of the aforementioned aluminum alloy core
material, there is an Al--Mn series alloy plate improved in high
temperature strength by manufacturing under predetermined
heat-treating conditions and rolling conditions. However, although
these Al--Mn series alloy plates are excellent in characteristics
as elementary substance, they can give simultaneously neither
brazing performance nor corrosion prevention performance (Japanese
Unexamined Laid-open Patent Publication No. 2000-104149 and
Japanese Unexamined Laid-open Patent Publication No.
2002-241910).
[0008] Moreover, as for the method for manufacturing a clad
material, in place of the aforementioned hot-rolling method,
various methods utilizing continuous casting of core materials have
been proposed (Japanese Unexamined Laid-open Patent Publication No.
H11-226699, Japanese Laid-open Patent Publication No. H8-509265 and
Japanese Laid-open Patent Publication No. 2002-248599).
[0009] Japanese Unexamined Laid-open Patent Publication No.
H11-226699 discloses a method for continuously manufacturing a clad
material in which a skin material is pressure-bonded to a core
material which is being sent out from a cast rolling mill with
pressure-bonding rolls disposed at the vicinity of the outlet side
of the rolling mill. Also disclosed in FIGS. 11e and 11f of
Japanese Laid-open Patent Publication No. H8-509265 is a method for
continuously casting a core material and cladding of the core
material and a skin material with pressure-bonding rolls disposed
at the outlet side of the cooling rollers of the cast rolling
mill.
[0010] On the other hand, disclosed in FIGS. 11a, 11b and 11c of
Japanese Laid-open Patent Publication No. H8-509265 is a method for
manufacturing a clad material in which casting of a core material
and pressure-bonding of the core material and the skin material are
simultaneously performed by supplying the skin material at the
inlet side of molten alloy with cooling rollers of the cast rolling
apparatus. Also disclosed in Japanese Laid-open Patent Publication
No. 2002-248599 is a method for supplying a skin material at the
inlet side of cooling rollers for casting a core material when
manufacturing a clad material in which the width of the skin
material is wider than that of the core material and the skin
material is embedded in the core material.
[0011] However, there were the following problems in the
manufacturing method of the aforementioned clad material.
[0012] That is, according to the method in which pressure-bonding
of the skin material to the core material is performed after the
casting of the core material, since it is necessary to arrange a
cast rolling mill and a pressure-bonding roll, the equipment
becomes complicated in structure, and the production rate is
restricted by the continuous casting rate of the core material.
Furthermore, deterioration of adhesiveness of the skin material due
to a segregation layer containing oxide formed on the surface at
the time of continuous cast rolling and deterioration of corrosion
characteristics at the interface cannot be suppressed.
[0013] On the other hand, according to the method for
simultaneously performing the casting of the core material and the
pressure-bonding of the skin material to the core material, since
the position where the skin material comes into contact with the
molten metal (core material) at the inlet side of the cooling
rollers becomes unstable, a part of the skin material may melt, or
even may be broken. Furthermore, according to Japanese Laid-open
Patent Publication No. 2002-248599, since the width of the core
material is larger than that of the skin material and therefore the
molten metal partially comes into contact with the cooling rollers,
the roll surface property changes, resulting in difficulty in
controlling the roll surface property for a long time.
[0014] The description herein of advantages and disadvantages of
various features, embodiments, methods, and apparatus disclosed in
other publications is in no way intended to limit the present
invention. Indeed, certain features of the invention may be capable
of overcoming certain disadvantages, while still retaining some or
all of the features, embodiments, methods, and apparatus disclosed
therein.
[0015] Other objects and advantages of the present invention will
be apparent from the following preferred embodiments.
DISCLOSURE OF INVENTION
[0016] The preferred embodiments of the present invention have been
developed in view of the above-mentioned and/or other problems in
the related art. The preferred embodiments of the present invention
can significantly improve upon existing methods and/or
apparatuses.
[0017] The present invention was made in view of the aforementioned
problems, and aims to provide a method for manufacturing a clad
material capable of keeping the surface property of cooling rollers
constant while keeping high cooling rate of a core material,
restraining deterioration of adhesiveness of a skin layer due to
contamination of non-metallic inclusion such as an oxide film
formed at the interface of the skin material and the core material,
and restraining occurrence of thickness variation of the skin
material after the cladding and/or breakage of the skin material
during the manufacturing process. Furthermore, the present
invention also aims to provide a clad material manufactured by the
aforementioned method and an apparatus for manufacturing a clad
material for executing the aforementioned method.
[0018] The method for manufacturing a clad material according to
the present invention has the following structures as recited in
Items (1) to (11).
[0019] (1) A method for manufacturing a clad material, comprising
the steps of:
[0020] continuously supplying molten metal into a gap between a
pair of cooling rollers to cast a core material; and
[0021] cladding skin materials on both surfaces of the core
material with hot rolling by continuously supplying the skin
materials on peripheral surfaces of the cooling rollers so that the
skin materials prevent direct contact between the cooling rollers
and the molten metal,
[0022] wherein the skin materials are supplied so as to come into
contact with the peripheral surfaces of the cooling rollers,
and
[0023] wherein a contact distance (L1) from a contact starting
point (P1) where the skin material begins to come into contact with
the cooling roller to a meeting point (P2) where the skin material
begins to come into contact with the molten metal is set to 100
times or more of a thickness (t1) of the skin material.
[0024] (2) The method for manufacturing a clad material as recited
in the aforementioned Item 1, wherein the core material and the
skin material are made of aluminum or its alloy.
[0025] (3) The method for manufacturing a clad material as recited
in the aforementioned Item 1, wherein the thickness (t1) of the
skin material is 20 to 400 .mu.m.
[0026] (4) The method for manufacturing a clad material as recited
in the aforementioned Item 2, wherein at least one of the skin
materials is made of Al--Si series alloy.
[0027] (5) The method for manufacturing a clad material as recited
in the aforementioned Item 4, wherein the Al--Si series alloy
consists essentially of
[0028] Si: 5 to 15 mass %,
[0029] Fe: 0.05 to 0.6 mass %,
[0030] Cu: 0.01 to 0.6 mass %,
[0031] Mn: 0.01 to 0.8 mass %,
[0032] Mg: 0.01 to 0.2 mass %,
[0033] Ti: 0.01 to 0.2 mass %, and
[0034] the balance being Al and inevitable impurities.
[0035] (6) The method for manufacturing a clad material as recited
in the aforementioned Item 2, wherein at least one of the skin
materials is made of Al--Zn series alloy.
[0036] (7) The method for manufacturing a clad material as recited
in the aforementioned Item 6, wherein the Al--Zn series alloy
consists essentially of
[0037] Si: 0.05 to 0.6 mass %,
[0038] Fe: 0.05 to 0.6 mass %,
[0039] Cu: 0.01 to 0.6 mass %,
[0040] Mn: 0.01 to 0.8 mass %,
[0041] Mg: 0.01 to 0.2 mass %,
[0042] Ti: 0.01 to 0.2 mass %,
[0043] Zn: 0.35 to 8.5 mass %, and
[0044] the balance being Al and inevitable impurities.
[0045] (8) The method for manufacturing a clad material as recited
in the aforementioned Item 1, wherein a thickness (t2) of the skin
material after hot roll cladding is 0.5 to 8 mm.
[0046] (9) The method for manufacturing a clad material as recited
in the aforementioned Item 2, wherein the molten metal to become
the core material consists essentially of
[0047] Si: 0.05 to 1.5 mass %,
[0048] Fe: 0.05 to 2 mass %,
[0049] Cu: 0.05 to 0.8 mass %,
[0050] Mn: 0.15 to 2.8 mass %,
[0051] at least one of elements selected from the group consisting
of Cr: 0.03 to 0.7 mass %, Mg: 0.01 to 0.2 mass %, Ti: 0.01 to 0.3
mass %, and Zn: 0.01 to 1.5 mass %, and
[0052] the balance being Al and inevitable impurities.
[0053] (10) The method for manufacturing a clad material as recited
in the aforementioned Item 9, wherein the molten metal further
includes at least one of elements selected from the group
consisting of Zr: 0.15 to 1.5 mass %, V: 0.03 to 1.5 mass %, and
Sc: 0.02 to 0.5 mass %.
[0054] (11) The method for manufacturing a clad material as recited
in any one of the aforementioned Items 1 to 10, wherein cold
rolling is performed after the hot roll cladding.
[0055] A clad material according to the present invention has the
following structures as recited in Items (12) to (15).
[0056] (12) A clad material in which skin materials are clad on
both surfaces of a core material, wherein the clad material is
manufactured by the steps of continuously supplying molten metal
into a gap between a pair of cooling rollers to cast a core
material, and cladding skin materials on both surfaces of the core
material with hot rolling by continuously supplying the skin
materials on peripheral surfaces of the cooling rollers so that the
skin materials prevent direct contact between the cooling rollers
and the molten metal, wherein the skin materials are supplied so as
to come into contact with the peripheral surfaces of the cooling
rollers, and wherein a contact distance (L1) from a contact
starting point (P1) where the skin material begins to come into
contact with the cooling roller to a meeting point (P2) where the
skin material begins to come into contact with the molten metal is
set to 100 times or more of a thickness (t1) of the skin
material.
[0057] (13) The clad material as recited in the aforementioned Item
12, wherein the clad material is cold rolled after the hot roll
cladding.
[0058] (14) The clad material as recited in the aforementioned Item
12, wherein an average dendrite secondary arm spacing of the core
material formed by the heat roll cladding is 0.1 to 10 .mu.m.
[0059] (15) The clad material as recited in any one of the
aforementioned Items 12 to 14, wherein the clad material is heat
exchanger component material.
[0060] The apparatus for manufacturing a clad material according to
the present invention has the following structures as recited in
Item (16).
[0061] (16) An apparatus for manufacturing a clad material,
comprising:
[0062] a pair of cooling rollers for continuously casting molten
metal passing through a gap formed between the cooling rollers;
[0063] a molten metal supplying portion for supplying the molten
metal to become a core material into the gap; and
[0064] a skin material supplying portion for supplying a skin
material on a peripheral surface of the cooling roller and making
the skin material come into contact with the peripheral surface of
the cooling roller before the skin material joins the molten
metal,
[0065] wherein the cooling rolls are rotated while continuously
supplying the molten metal and the skin material to the cooling
rolls to thereby continuously clad the skin materials to both
surfaces of the core material.
EFFECTS OF THE INVENTION
[0066] According to the manufacturing method of the clad material
of the invention as recited in the aforementioned Item (1), since
the skin materials are joined to the molten metal in a state in
which the skin material is cooled, the molten metal is solidified
quickly by being cooled by the cooling rollers. Therefore, a core
material having high hardness can be cast and the skin materials
can be pressure-bonded to both surfaces of the core material. Since
the skin material is cooled in advance, melting and/or fusing of
the skin material due to the heat of the molten metal M can be
prevented, and a clad material can be manufactured efficiently
without reducing the cooling rate of the core material. Moreover,
since the aforementioned skin materials are pressure-bonded during
the solidification process of the core material, high adhesion can
be attained. Furthermore, since the cooling rollers and the molten
metal are intercepted by the skin material, the alteration and
deterioration of the roll surface property due to adhesion of the
molten metal can be prevented.
[0067] According to the invention as recited in the aforementioned
Item (2), the aforementioned clad material which consists of
aluminum or its alloy can be manufactured.
[0068] According to the invention as recited in the aforementioned
Item (3), tension control of the skin material can be performed
smoothly, and sufficient cooling rate of the core material can be
secured.
[0069] According to the invention as recited in the aforementioned
Item (4), an aluminum brazing clad material with brazing material
clad on the surface can be manufactured.
[0070] According to the invention as recited in the aforementioned
Item (5), the aluminum brazing clad material excellent in
especially brazing performance can be manufactured.
[0071] According to the invention as recited in the aforementioned
Item (6), the aluminum brazing clad material excellent in corrosion
resistance in which a sacrificial corrosion layer is formed on the
surface can be manufactured.
[0072] According to the invention as recited in the aforementioned
Item (7), the aluminum brazing clad material excellent in
especially corrosion resistance can be manufactured.
[0073] According to the invention as recited in the aforementioned
Item (8), molten metal can be supplied stably and it is possible to
secure the heat releasing capacity from the cooling rollers.
[0074] According to the invention as recited in the aforementioned
Item (9), an aluminum brazing clad material excellent in strength
even at high temperature and excellent in corrosion resistance can
be manufactured.
[0075] According to the invention as recited in the aforementioned
Item (10), the aluminum material excellent in especially high
temperature strength can be manufactured.
[0076] According to the invention as recited in the aforementioned
Item (11), the clad material having a prescribed thickness can be
manufactured.
[0077] The clad material according to the invention as recited in
the aforementioned Item (12) is excellent in adhesiveness property
between the skin materials and the core material, or is a useful
clad material to which various characteristics, such as brazing
performance, corrosion resistance and strength, are further added.
Furthermore, the clad material is excellent in workability.
[0078] According to the invention as recited in the aforementioned
Item (13), a clad material having a prescribed thickness can be
obtained.
[0079] According to the invention as recited in the aforementioned
Item (14), a clad material especially excellent in strength can be
obtained.
[0080] According to the invention as recited in the aforementioned
Item (15), the clad material is useful as a heat exchanger
structure component material.
[0081] According to the manufacturing apparatus of a clad material
of the invention as recited in the aforementioned Item (16), the
manufacturing method of the present invention is executed and a
clad material can be manufactured efficiently.
[0082] The above and/or other aspects, features and/or advantages
of various embodiments will be further appreciated in view of the
following description in conjunction with the accompanying figures.
Various embodiments can include and/or exclude different aspects,
features and/or advantages where applicable. In addition, various
embodiments can combine one or more aspect or feature of other
embodiments where applicable. The descriptions of aspects, features
and/or advantages of particular embodiments should not be construed
as limiting other embodiments or the claims.
BRIEF DESCRIPTION OF DRAWINGS
[0083] FIG. 1 is a schematic view showing an apparatus structure
for executing a method for manufacturing a clad material according
to the present invention.
[0084] FIG. 2 is a perspective view showing a brazed article used
in a brazing test.
BEST MODE FOR CARRYING OUT THE INVENTION
[0085] In the following paragraphs, some preferred embodiments of
the invention will be described by way of example and not
limitation. It should be understood based on this disclosure that
various other modifications can be made by those in the art based
on these illustrated embodiments.
[0086] A method for manufacturing a clad material according to a
preferable embodiment of the present invention will be described in
detail with reference to the clad material manufacturing apparatus
1 shown in FIG. 1.
[0087] In FIG. 1, the reference numeral 2a and 2b denote a pair of
cooling rollers disposed at a certain distance, the reference
numeral 3 denotes a nozzle which injects molten metal M supplied
from a molten-metal preparation portion, such as a melting furnace
and a tundish (not shown), into the gap between the aforementioned
cooling rollers 2a and 2b. The aforementioned nozzle 3 sets the
meeting point P2 of the molten metal M and the skin material 10a
and 10b by the opening width and the set position. The
aforementioned nozzle 3 demonstrates effective roles for preventing
melt breakage of the skin material and holding the clad ratio (skin
material/core material/skin material) constant. The reference
numeral 4a (4b) denotes a holding roll for holding down the skin
material 10a (10b) continuously supplied by unwinding the skin
material coil (not shown) toward the cooling roller 2a (2b). By
adjusting the holding position of the holding roll 4a (4b), the
contact starting point P1 where the skin material 10a (10b) begins
to come into contact with the cooling roller 2a (2b) is set. The
reference numeral 11 denotes a plate-shaped core material made of
cast molten metal M, and the reference numeral 12 denotes a
three-layered clad material in which the skin materials 10a and 10b
are clad on both surfaces of the aforementioned core material
11.
[0088] In the manufacturing method of the clad material according
to the present invention, when supplying the skin material 10a
(10b) to the cooling roller 2a (2b), the skin material 10a (10b) is
cooled by coming into contact with the peripheral surface of the
cooling roller 2a (2b) before joining the molten metal M, and
therefore the skin material 10a (10b) joins the molten metal M in a
cooled state. For this reason, the molten metal M supplied to the
gap between the cooling rollers 2a and 2b is quickly solidified by
being cooled by the cooling roller 2a (2b) even via the skin
material 10a (10b), and the skin material 10a (10b) is
pressure-bonded and clad on both surfaces of the core material 11.
Furthermore, since the skin material 10a (10b) is to be
pressure-bonded to the core material 11 during the solidification
process of the core material 11, contamination, such as an oxide
film, to the interface between the skin material 10a (10b) and the
core material 11 can be prevented, resulting in excellent
adhesiveness of the skin material 10a (10b) to the core material
11. Since the aforementioned skin material 10a (10b) is cooled
beforehand, the melting and fusing of the skin material due to the
heat of the molten metal M can be prevented, and therefore the clad
material 12 can be manufactured efficiently without reducing the
cooling rate of the core material 11. Moreover, since the molten
metal M and the cooling roller 2a (2b) are intercepted by the
aforementioned skin material 10a (10b), alteration and/or
deterioration of the roll surface property due to the adhesion of
the molten metal M can be prevented.
[0089] The contact distance L1 of the skin material 10a (10b) along
which the aforementioned skin material 10a(10b) is pre-cooled by
the cooling roller (2a) 2b, namely, the distance from the contact
starting point P1 where the skin material 10a (10b) comes into
contact with the cooling roller 2a (2b) to the meeting point P2
where the skin material 10a (10b) comes into contact with the
molten metal M, it is necessary to set such that the contact
distance L1 is set to a length of 100 times or more of the
thickness t1 of the skin material 10a (10b) in order to fully cool
the skin material 10a (10b) and to acquire the aforementioned
effects. More preferably, the contact distance L1 is set to a
length of 200 times to 100,000 times of the thickness t1 of the
skin material 10a (10b).
[0090] It is possible to attain the aforementioned manufacturing
conditions by setting the contact distance L1 so that the ratio of
the contact distance to the thickness of the skin material (L1/t1)
falls within the aforementioned range. For example, by changing the
diameter of the cooling rollers 2a (2b) and the contact starting
point P1 where the skin material 10a (10b) begins to come into
contact with the cooling roller 2a (2b) so as to meet the
aforementioned range, the range of the roller with which the skin
material 10a (10b) is in contact, namely, the contact distance L1,
can be adjusted. In cases where the contact distance L1 is
represented by a center angle as seen from the center of the
cooling roller 2a (2b), it is preferable to adjust the range of the
center angle so as to fall within the range of from 10 to
270.degree.. If it falls within this range, it becomes easy to
arrange the devices, and the skin material can be stably wound on
the cooling roller 2a(2b). It is more preferable to adjust the
range so as to fall within the range of from 150 to
180.degree..
[0091] It is preferable that the thickness t1 of the aforementioned
skin material 10a (10b) is 20 to 400 .mu.m. If it is less than 20
.mu.m, it becomes difficult to control the tension of the unwinding
roll, which in turn makes it difficult to perform continuation
operation due to the possible breakage of the skin material. On the
other hand, if it exceeds 400 .mu.m, the heat capacity of the skin
material 10a (10b) increases. Therefore, the heat releasing
capacity of the cooling roller 2a (2b) becomes insufficient,
resulting in insufficient cooling rate. The preferable thickness t1
of the skin material 10a (10b) is 20 to 200 .mu.m. The thickness of
the skin material 10a (10b) is not required to be the same in both
sides, and the skin materials different in thickness can be
employed. Accordingly, the contact distances L1 of both skin
materials can also be different with each other.
[0092] The thickness t2 of the core material 11 after the hot
cladding is preferably 0.5 to 8 mm. Since the present invention
employs continuous casting using a pair of cooling rollers 2a and
2b, if the plate thickness t2 after the cladding is less than 0.5
mm, the roll gap is too narrow to stably supply molten metal M. On
the other hand, if the thickness exceeds 8 mm, the heat releasing
capacity through the cooling roller 2a (2b) becomes insufficient,
which makes it difficult to secure sufficient cooling rate of the
core material. The preferable thickness t2 of the core material 11
is 0.8 to 6 mm.
[0093] As will be understood from the above, it is possible to cast
a core material 11 excellent in high-temperature strength and
efficiently manufacture a three-layered structural clad material 12
with skin materials 10a and 10b clad on both surfaces of the core
material 11.
[0094] As for the aforementioned cooling rollers, the number of
revolutions of the cooling rollers, and the materials of the
cooling rollers, it is possible to employ conventionally known
ones, provided that cooling conditions of materials are
sufficiently met under the aforementioned L1/t1 condition. For
example, the diameter of the roller is preferably 100 to 1,000 mm
since such a cooling roll can be easily manufactured or obtained
and therefore the entire apparatus can be constituted at lower
cost. Furthermore, the number of revolutions of the cooling roller
is preferably 1 to 200 m/min., more preferably 5 to 150 m/min. in
circumferential velocity. As the materials of the cooling rollers,
aluminum or its alloy, copper or its alloy, and iron or its alloy
can be exemplified.
[0095] In the aforementioned clad material 12, the materials of the
core material 11 and the skin material 10a and 10b are metal, and
aluminum and its alloy can be exemplified as such metal. The clad
material made of aluminum or its alloy can be used as component
material which constitutes, for example, fluid passages, tubes,
heat releasing fins of heat exchangers.
[0096] As the core material and the skin material made of aluminum
or its alloy, the following material can be recommended.
[0097] As for the skin material, it is preferable to use Al--Si
series alloy which functions as brazing material and Al--Zn series
alloy which gives corrosion resistance.
[0098] As the aforementioned Al--Si series alloy, it is preferable
to use alloy consisting of Si: 5 to 15 mass %, Fe: 0.05 to 0.6 mass
%, Cu: 0.01 to 0.6 mass %, Mn: 0.01 to 0.8 mass %, Mg: 0.01 to 0.2
mass %, Ti: 0.01 to 0.2 mass %, and the balance being Al and
inevitable impurities.
[0099] The reasons of adding each element in the aforementioned
Al--Si series alloy are as follows.
[0100] Si is an element which makes the alloy function as brazing
material by lowering the melting point of the alloy. The preferable
Si content is 6.5 to 11 mass %. Fe is an element to be added to
improve the wettability of brazing material, and if the content is
less than 0.05 mass %, the effects will become poor. To the
contrary, if it exceeds 0.6 mass %, large and rough intermetallic
compound will be generated, which gives adverse effects on
corrosion resistance. The preferable Fe content is 0.1 to 0.5 mass
%. Cu is an element to be added to control the electric potential
of the skin material (Al--Si series alloy). For example, in cases
where the clad material 12 is used as a brazing tube of a heat
exchanger, the electric potential of the brazing material becomes
unnecessarily less noble with respect to the tube. Therefore, Cu is
added to restrain an occurrence of preferential corrosion of
fillets. The preferable Cu content is 0.02 to 0.5 mass %. Mn is an
element to be added to control the electric potential of the
brazing material like Cu. If the content exceeds 0.8 mass %, the
flowing characteristics of the brazing material may be inhibited.
The preferable Mn content is 0.02 to 0.6 mass %. Mg is an element
to be added to improve the strength. If it is less than 0.01 mass
%, the effects become poor. To the contrary, it exceeds 0.2 mass %,
the brazing performance will be inhibited remarkably. The
preferable Mg content is 0.01 to 0.1 mass %. Ti is an element to be
added to control the electric potential of the brazing material.
The preferable Ti content is 0.01 to 0.1 mass %.
[0101] As the aforementioned Al--Zn series alloy, it is preferable
to use an alloy consisting of Si: 0.05 to 0.6 mass %, Fe: 0.05 to
0.6 mass %, Cu: 0.01 to 0.6 mass %, Mn: 0.01 to 0.8 mass %, Mg:
0.01 to 0.2 mass %, Ti: 0.01 to 0.2 mass %, Zn: 0.35 to 8.5 mass %,
and the balance being Al and inevitable impurities.
[0102] The reasons of adding each element in the aforementioned
Al--Zn series alloy are as follows.
[0103] Zn is an element which is dissolved in Al to make the skin
material function as a sacrificial corrosion layer of the core
material. The preferable Zn content is 0.35 to 6 mass %. Si is an
element to be added to improve the strength, and the preferable Si
content is 0.1 to 0.5 mass %. Although Fe is an element to be added
to improve the strength, if it exceeds 0.6 mass %, large and rough
intermetallic compounds will be generated, which may cause a
deterioration of corrosion resistance. The preferable Fe content is
0.1 to 0.5 mass %. Cu is an element to be added to control the
electric potential of the skin material. The preferable Cu content
is 0.02 to 0.3 mass %. Mn is an element to be added to control the
electric potential of the skin material. The preferable Mn content
is 0.02 to 0.6 mass %. Mg is an element to be added to improve the
strength. If it is less than 0.01 mass %, the effects cannot be
obtained. To the contrary, if it exceeds 0.2 mass %, the brazing
performance may be remarkably inhibited. The preferable Mg content
is 0.01 to 0.1 mass %. Ti is an element to be added to control the
electric potential of the skin material. The preferable Ti content
is 0.01 to 0.1 mass %.
[0104] The skin material having the aforementioned composition can
be clad on at least one surface of the core material. A skin
material to be clad on the other surface of the core material can
be a skin material having a composition the same as or different
from that of the aforementioned skin material.
[0105] On the other hand, as the core material 11, i.e., the molten
metal M, it is preferable to use alloy consisting of at least one
of elements selected from the group consisting of Si: 0.05 to 1.5
mass %, Fe: 0.05 to 2 mass %, Cu: 0.05 to 0.8 mass %, Mn: 0.15 to
2.8 mass %, at least one element selected from the group consisting
of Cr: 0.03 to 0.7 mass %, Mg: 0.01 to 0.2 mass %, Ti: 0.01 to 0.3
mass % and Zn: 0.01 to 1.5 mass %, and the balance being Al and
inevitable impurities. Furthermore, in the composition of the
aforementioned molten metal M, it is preferable to further contain
at least one element selected from the group consisting of Zr: 0.15
to 1.5 mass %, V: 0.03 to 1.5 mass %, and Sc: 0.02 to 0.5 mass
%.
[0106] The reasons of adding each element in the composition of the
aforementioned core material are as follows.
[0107] Si is an element to be added to improve the strength, and
the preferable Si content is 0.5 to 1.2 mass %. Fe is an element to
be added to improve the strength. If it exceeds 2 mass %,
intermetallic compounds, such as an Al--Fe--Mn--Si series, will be
generated, which may inhibit corrosion resistance. The preferable
Fe content is 0.1 to 0.5 mass %. Cu is an element to be added to
control the electric potential, cause the electric potential to be
noble than the electric potential of the skin material by adding
Cu, and perform corrosion prevention of the core material. The
preferable Cu content is 0.05 to 0.6 mass %. Mn is an element to be
added to improve the strength, especially to improve the strength
at high temperature. The preferable Mn content is 0.5 to 2.5 mass
%. Cr is an element to be added to improve the high temperature
strength, and the preferable Cr content is 0.05 to 0.3 mass %. Mg
is an element which is dissolved in Al to improve the high
temperature strength, and the preferable Mg content is 0.05 to 0.2
mass %. Ti makes electric potential noble, and is an element to be
added to change the corrosion from pitting corrosion to layer
corrosion, and the preferable Ti content is 0.05 to 0.25 mass %. Zn
is an element added to control the electric potential, and the
preferable Zn content is 0.1 to 1 mass %.
[0108] Zr, V, and Sc which are added arbitrarily are elements to be
added for the purpose of raising the recrystallizing temperature
and raising the high temperature strength. The preferable Zr
content is 0.15 to 0.8 mass %. The preferable V content is 0.1 to 1
mass %. The preferable Sc content is 0.04 to 0.5 mass %. It is
sufficient that at least one of Zr, V, and Sc is included. However,
two or all of three elements can be included.
[0109] The clad material manufactured from the aluminum or aluminum
alloy mentioned above can be formed into a predetermined thickness
by further subjecting it to cold rolling if necessary. Moreover,
heat treating after the cladding or cold rolling can also be
performed arbitrarily.
[0110] The clad material manufactured by the manufacturing method
of the present invention is excellent in high-temperature strength
due to the rapid solidification of the core material. Furthermore,
since the breakage thereof at the time of machining seldom occurs,
the clad material can be a clad material excellent in workability.
Especially in the crystalline structure of the core material, the
clad material whose average dendrite secondary arm spacing (DAS) is
0.1 to 10 .mu.m has high-temperature strength. The more preferable
average dendrite secondary arm spacing is 0.1 to 8 .mu.m.
Furthermore, the skin material to which brazing performance and
corrosion prevention performance was given by the skin material
having the prescribed components can be preferably used as a
brazing material of heat exchanger components, such as a fluid
passage, a tube and a heat releasing fin, to be used in high
temperature environment. Especially, the skin material can be used
as structural components of heat exchangers using CO.sub.2
refrigerant that especially excellent high temperature strength is
required.
[0111] The manufacturing apparatus for clad material according to
the present invention is not limited to the manufacturing apparatus
1 having the structure shown in FIG. 1, but can employ various
structures having the same function.
[0112] The cooling roller in the manufacturing apparatus of the
present invention corresponds to the cooling roller 2a and 2b of
the manufacturing apparatus 1 of the illustrated embodiment.
Similarly, the molten-metal supplying portion corresponds to a
molten-metal preparation portion which is located outside the
drawing and arranged in front of the nozzle 3. The skin material
feeding portion corresponds to the aforementioned holding roll 4a
(4b) and the tension roll for adjusting the tension of the skin
material coil located outside the drawing or the tension of the
skin member, etc.
EXAMPLES
[0113] It should be understood that the following examples do not
limit the scope of the invention.
[0114] Using the apparatus 1 for manufacturing the clad material as
shown in FIG. 1 and explained above, the three-layered clad
material 12 of the present invention was manufactured.
[0115] In each following Examples 1 to 3, as the alloy constituting
a core material and a skin material, the aluminum alloys having the
chemical composition shown in Table 1 were used. TABLE-US-00001
TABLE 1 Alloy Chemical composition (mass %), the balance being Al
and inevitable impurities No. Si Fe Cu Mn Mg Cr Ni Zn Ti Zr V Sc
(a) 0.10 0.25 0.02 0.01 0.01 <0.01 <0.01 0.02 0.01 <0.01
<0.01 <0.01 (b) 0.08 0.20 0.02 0.01 0.01 <0.01 <0.01
0.04 0.01 0.18 <0.01 <0.01 (c) 0.25 0.50 0.12 0.02 0.01 0.01
<0.01 0.04 0.05 <0.01 <0.01 <0.01 (d) 0.25 0.40 0.15
1.05 0.01 0.01 <0.01 0.05 0.02 <0.01 <0.01 <0.01 (e)
0.25 0.40 0.15 0.95 0.01 0.20 <0.01 0.05 0.05 0.18 <0.01
<0.01 (f) 7.85 0.65 0.07 0.04 0.02 0.01 <0.01 0.10 0.02
<0.01 <0.01 <0.01 (g) 0.30 0.60 0.14 0.05 1.52 0.04
<0.01 0.15 0.05 <0.01 <0.01 <0.01 (h) 0.20 0.35 0.07
0.07 2.25 0.24 <0.01 0.08 0.05 <0.01 <0.01 <0.01 (i)
0.48 0.33 0.05 0.04 0.55 0.03 <0.01 0.04 0.03 <0.01 <0.01
<0.01 (j) 0.20 0.42 0.05 0.04 0.03 <0.01 <0.01 1.15 0.10
<0.01 <0.01 <0.01 (k) 0.30 0.45 1.65 0.25 2.55 0.22
<0.01 5.55 0.10 0.18 <0.01 <0.01 (l) 0.25 0.40 0.18 1.05
0.01 0.01 <0.01 0.05 0.02 <0.01 <0.01 <0.01 (m) 4.55
0.55 0.06 0.04 0.02 0.01 <0.01 2.20 0.02 <0.01 <0.01
<0.01 (n) 8.85 0.65 0.07 0.04 0.02 0.01 <0.01 2.20 0.02
<0.01 <0.01 <0.01 (o) 15.80 0.64 0.07 0.04 0.02 0.01
<0.01 2.20 0.02 <0.01 <0.01 <0.01 (p) 0.20 0.42 0.05
0.04 0.03 <0.01 <0.01 0.15 0.10 <0.01 <0.01 <0.01
(q) 0.20 0.42 0.05 0.04 0.03 <0.01 <0.01 2.55 0.10 <0.01
<0.01 <0.01 (r) 0.20 0.42 0.05 0.04 0.03 <0.01 <0.01
10.50 0.10 <0.01 <0.01 <0.01 (s) 0.30 0.38 0.05 1.05 0.01
0.01 <0.01 1.50 0.02 <0.01 <0.01 <0.01 (t) 8.50 0.45
0.10 0.04 0.02 0.01 <0.01 1.50 0.04 <0.01 <0.01 <0.01
(u) 0.60 0.40 0.35 0.05 0.10 0.05 <0.01 0.85 0.05 <0.01
<0.01 <0.01 (v) 0.80 0.50 0.35 1.55 0.10 0.15 <0.01 0.80
0.18 <0.01 <0.01 <0.01 (w) 1.10 0.60 0.35 1.55 0.10 0.25
<0.01 0.80 0.18 <0.01 <0.01 <0.01 (x) 1.10 0.65 0.45
1.55 0.15 0.25 <0.01 0.80 0.18 0.25 <0.01 <0.01 (y) 1.10
0.65 0.45 1.55 0.15 0.25 <0.01 0.80 0.18 <0.01 0.20 <0.01
(z) 1.10 0.65 0.45 1.55 0.15 0.25 <0.01 0.80 0.18 <0.01
<0.01 0.25
Example 1
[0116] This Example 1 is an example about the stability of the skin
material and the structure of the core material by the heat
cladding conditions.
[0117] As a skin material 10a and 10b, an ingot made of the alloys
Nos. (a), (c), (f) and (j) shown in Table 1 and manufactured by a
semi-continuous casting method was subjected to hot rolling,
intermediate annealing at 370.degree. C..times.4 h, then cold
rolling and intermediate annealing if needed, to thereby obtain a
material having a thickness t1 of 0.20 mm.
[0118] As for the inventive examples Nos. 1 to 10 and the
comparative examples Nos. 11 to 19, and 21 shown in Table 2, using
the aforementioned clad material manufacturing apparatus 1, a
three-layered heat rolled clad material 12 with the skin materials
10a and 10b clad on both surfaces of the core material 11 was
manufactured.
[0119] In detail, in the state in which the skin materials 10a and
10b whose reference sign is shown in Table 2 were set and rotated
with the skin material 10a and 10b contacting the peripheral
surface of the cooling rollers 2a and 2b, the molten metal M having
the core material compositions (b), (d), (e), (g), (h), (i) and (k)
shown in Table 2 was poured from the above. At this time, the
target thickness of the core material 11 after the heat roll
cladding was set to 4.0 mm. Moreover, the contact distance L1 from
the contact starting point P1 where the aforementioned skin
material 10a (10b) begins to come into contact with the cooling
roller 2a (2b) to the meeting point P2 where the skin material
begins to come into contact with the molten metal M was set to 100
or 150 times of the thickness t1 of skin material 10a (10b) in the
Inventive examples Nos. 1 to 10, and set to 50 or 80 times of the
thickness t1 of the skin material 10a (10b) in the comparative
examples Nos. 11 to 19, and 21. Although the pouring temperature of
the molten metal M was different depending on the composition of
the core material 11, in order to prevent dissolution of the skin
material 10a (10b), it was set such that it became higher than the
solidification start temperature by about 5 to about 30.degree. C.
Moreover, the peripheral speed of the cooling roller 2a (2b) was
set to 30 m/min.
[0120] About the manufactured three-layered clad materials 12, the
skin material breakage and the skin material melting ratio were
evaluated by the following standard, and the average dendrite
secondary arm spacing (DAS) of the core material was also measured.
These results are shown in Table 2.
(Skin Material Breakage)
[0121] In the case where there was a breakage during the
manufacturing the three-layered clad material 12 of 100 m length,
it was noted as "yes," and in the case where there was no breakage,
it was noted as "no." A skin material noted as "no" skin material
breakage was evaluated as a good article.
(Skin Material Melting Rate)
[0122] The skin material melting rate was expressed by percentage
obtained by performing five-point sampling from the organization
observation of the cross-section of the hot rolled clad plate and
averaging the five maximum values of the molten portions of the
skin material and then dividing the average value by the original
thickness of the skin material. Here, it was calculated under the
assumption that there was no area reduction of the skin material
due to rolling. In the case where the skin material melting rate
was 5% or less, it was evaluated as a good article.
(Average DAS)
[0123] An arbitrary length L parallel to the dendrite principal
axis was obtained as an average value by performing five point
measurements at the value by divided by the number N of the
secondary arm which exists therein. In the case where the average
DAS was 10 .mu.m less was estimated as a good article.
[0124] Subsequently, after cold rolling each hot rolled clad
material 12 into a thickness of 110 .mu.m, heat treating of
600.degree. C..times.10 min. was performed. This heat treating was
heat-treatment supposing brazing. As for the inventive example No.
6 and the comparative example No. 16, they were subjected to heat
treating of 170.degree. C..times.5 h. As for the inventive example
No. 9 and the comparative example No. 19, they were subjected to
heat treating of 120.degree. C..times.3 h. The heat treatment was a
post-aging treatment intended to improve the strength of the core
material.
[0125] About the clad material after the aforementioned cold
rolling and heat treating, the tensile strength at ordinary
temperature and the tensile strength after holding at 180.degree.
C..times.10 h were measured. These results are shown in Table
2.
[0126] On the other hand, as for the comparative example No. 20
shown in Table 2, the core material had the composition (b) and the
skin material had the composition (f) shown in Table 1. Initially,
the ingot manufactured by the semi-continuous casting method was
subjected to pre-heating and hot rolling after cutting the surface
portion. The skin material having a thickness of 20 mm and the core
material having a thickness of 400 mm after the surface cutting of
the ingot surface were hot rolled to thereby obtain a hot rolled
plate having a total thickness of 5 mm. Furthermore, the hot rolled
plate with a thickness of 5 mm was cold-rolled into a thickness of
110 .mu.m, and then subjected to heat treatment of 600.degree.
C..times.10 min.
[0127] The skin material breakage, skin material melting rate, and
core material average DAS of the hot rolled plate was evaluated.
The skin material breakage and the skin material melting rate were
evaluated by the same method as in the aforementioned invention.
The core material average DAS was the value of the central portion
of the ingot (400 mm thickness) having the composition (b) to be
used as a core material. Moreover, as to the cold rolled plate with
a thickness of 110 mm, the tensile strength after 10 hours holding
at ordinary temperature and 180.degree. C. was measured. These
results are shown in Table 2. TABLE-US-00002 TABLE 2 Hot rolled
clad material Cold rolling Clad Material composition (three layered
clad) Total thickness Heat treatment material Skin/core/ Thickness
of the Targeted thickness of after the cold Heating Late aging No.
skin skin t1 (mm) of the core (mm) L1/t1 rolling (.mu.m) conditions
conditions Invention 1 (a)(b)(a) 0.20 4.0 100 110 600.degree. C.
.times. 10 min -- 2 (c)(b)(c) 0.20 4.0 100 110 -- 3 (f)(d)(f) 0.20
4.0 100 110 -- 4 (f)(e)(f) 0.20 4.0 100 110 -- 5 (j)(e)(j) 0.20 4.0
100 110 -- 6 (f)(g)(f) 0.20 4.0 100 110 170.degree. C. .times. 5 h
7 (f)(h)(f) 0.20 4.0 100 110 -- 8 (f)(i)(f) 0.20 4.0 100 110 -- 9
(f)(k)(f) 0.20 4.0 100 110 120.degree. C. .times. 3 h 10 (a)(b)(a)
1.20 4.0 150 110 -- Comp. 11 (a)(b)(a) 0.20 4.0 50 110 600.degree.
C. .times. 10 min -- 12 (c)(b)(c) 0.20 4.0 50 110 -- 13 (f)(d)(f)
0.20 4.0 50 110 -- 14 (f)(e)(f) 0.20 4.0 50 110 -- 15 (j)(e)(j)
0.20 4.0 50 110 -- 16 (f)(g)(f) 0.20 4.0 50 110 170.degree. C.
.times. 5 h 17 (f)(h)(f) 0.20 4.0 50 110 -- 18 (f)(i)(f) 0.20 4.0
50 110 -- 19 (f)(k)(f) 0.20 4.0 50 110 120.degree. C. .times. 3 h
20 (f)(b)(f) 20/400/200 mm, hot roll clad 110 -- into total
thickness of 5 mm 21 (a)(b)(c) 0.20 4.0 80 110 -- Clad Quality of
heat rolled clad material Tensile strength material Skin Skin
melting Core average Normal temp. 180.degree. C. No. breakage rate
(%) DAS (.mu.m) strength (MPa) strength (MPa) Invention 1 No <1
5.2 110 65 2 No <1 4.8 115 67 3 No 3 3.8 135 78 4 No 3 4.2 145
82 5 No <1 4.4 143 80 6 No 2 6.0 125 75 7 No 3 6.5 180 110 8 No
3 6.2 210 170 9 No 3 5.5 480 210 10 No <1 4.9 111 66 Comp. 11
Yes 6 12.4 98 59 12 Yes 6 13.2 102 60 13 Yes 20 11.3 115 70 14 Yes
22 11.5 120 72 15 Yes 7 12.0 118 69 16 Yes 14 16.3 120 72 17 Yes 12
14.9 175 104 18 Yes 13 15.5 180 111 19 No 7 13.8 410 195 20 Yes 6
25.2 75 48 21 Yes 6 11.5 110 60
[0128] From the result shown in Table 2, it was confirmed that in
each invention manufactured by the method of the present invention
the skin material was not broken, there was very few melting of the
skin material, and it was stably manufactured. Moreover, in the
manufactured clad material, it was confirmed that the average DAS
was 10 .mu.m or less, and it was excellent in high temperature
strength.
Example 2
[0129] This Example 2 is an example about brazing performance and
corrosion resistance by the skin material components and the skin
material.
[0130] As a skin material 10a and 10b, an ingot manufactured from
the alloys Nos. (m) to (r) in Table 1 by a semi-continuous casting
method was subjected to hot rolling, intermediate annealing at
370.degree. C..times.4 h, then cold rolling and intermediate
annealing if needed, to thereby obtain a material having a
thickness t1 of 0.35 mm.
[0131] About the inventive examples Nos. 22 to 29 shown in Table 3,
using the alloy having the composition shown in Table 1 as molten
metal M to be used as a core material, a three-layered clad
material 12 in which skin materials 10a and 10b were
pressure-bonded to the both surfaces of the core material 11 using
the aforementioned apparatus 1 for manufacturing a clad material
according to the example 1 was manufactured. In manufacturing, the
target thickness of the core material 11 after the hot roll
cladding was set to 5.0 mm. The contact distance L1 from the
contact starting point P1 to the cooling roller 2a (2b) of the
aforementioned skin material 10a (10b) to the meeting point P2
where the skin material comes into contact with the molten metal M
was set to 200 times of the thickness t1 of skin material 10a
(10b). The remaining conditions were set to the same as in Example
1.
[0132] Subsequently, each heat rolled clad material 12 was
cold-rolled into a thickness of 110 .mu.m, and then subjected to a
heat treatment of 600.degree. C..times.10 min.
[0133] About the clad material after the cold rolling and heat
treatment, the tensile strength at ordinary temperature, the
tensile strength after 180.degree. C..times.10 h holding, breakage
of the skin material, melting rate of the skin material, the
quality of hot rolled clad material with an average DAS were
measured or evaluated. These results are shown in Table 3.
[0134] Moreover, as to the cold-rolled three-layered clad material
12, the brazing performance and the corrosion resistance were
evaluated by the following method.
(Brazing Performance)
[0135] As to the inventive examples No. 22, 24, 25, 28 and 29 using
(m), (n), and (o) as a skin material, using the aluminum alloy
having the composition (s) shown in Table 1, it was rolled into a
sheet having a thickness of 80 .mu.m and processed into the fin 20
shown in FIG. 2. Moreover, as to the inventive examples Nos. 23, 26
and 27 using (p), (q) and (r) as a skin material, a three-layered
clad material (5 .mu.m/70 .mu.m/5 .mu.m, the total thickness of 80
.mu.m) having compositions (n), (s) and (n) shown in Table 1 was
manufactured, and then processed into the fin 20 shown in FIG. 2 in
the same manner as mentioned above. Each of the aforementioned fins
(20) had a fin thickness (Ft): 80 .mu.m, a fin pitch (Fp): 2.0 mm
and a fin height (Fh): 8 mm.
[0136] And as shown in FIG. 2, fins 20 and 20 were attached to both
surfaces of the aforementioned three-layered clad material 12, and
flux was applied thereto. Then, they were subjected to a brazing
test by heating at 600.degree. C..times.10 min.
[0137] About these brazed articles, the junction rate and erosion
were investigated. In the evaluation of the junction rate, the
length that the fin 20 was detached was measured by cutting the
fin, and calculated by the following formula: [1-(fin detached
length)/(the entire fin joining portion)].times.100. In the case
where the calculated result was 80% or more, it was shown as
".smallcircle.." In the case where the calculated result was less
than 80%, it was shown as "x." In the erosion valuation, in cases
where the erosion depth was less than 20 .mu.m, it was shown as
".smallcircle.," and in cases where the erosion depth exceeded 20
.mu.m, it was shown as "x."
(Corrosion Resistance)
[0138] A brazed article constituted by the three-layered clad
material 12 and fin 20 subjected to the brazing test was subjected
to SWAAT Test (Synthetic sea Water Acetic Acid salt spray Test)
defined in ASTM-G85-A3 to investigate generation of apertures and
fin detaching performances. The test conditions were as follows.
Corrosion test liquid adjusted so as to be pH3 by adding acetic
acid to artificial seawater according to ASTM D1141 was used. A
cycle of spraying the corrosion test liquid against the article for
0.5 hours and holding the article for 1.5 hours under the wet
condition was repeated for 960 hours.
[0139] In evaluating the generation of pitting corrosion, in cases
where no through-hole was formed in the clad material 12 after 960
hours, it was noted as ".smallcircle.," and in cases where
through-holes were formed, it was noted as "x." In evaluating the
fin detachment, the sample fin subjected to the corrosion test was
cut, and the similar evaluation as in the joint rate was performed.
As a result, in cases where the rate was 80% or more, it was noted
as ".smallcircle.," and in cases where the rate was less than 80%,
it was noted "x." TABLE-US-00003 TABLE 3 Hot rolled clad material
Material composition (three layered clad) Cold rolling Clad
Targeted Total thickness Tensile strength material Thickness of the
thickness of of after the cold Heat treatment Normal temp.
180.degree. C. No. Skin/core/skin skin t1 (mm) the core (mm) L1/t1
rolling (.mu.m) Heating conditions strength (MPa) strength (MPa)
Invention 22 (n)(l)(n) 0.35 5.0 200 110 600.degree. C. .times. 10
min 140 80 23 (q)(l)(q) 0.35 5.0 200 110 135 78 24 (m)(l)(m) 0.35
5.0 200 110 137 78 25 (o)(l)(o) 0.35 5.0 200 110 142 83 26
(p)(l)(p) 0.35 5.0 200 110 130 78 27 (r)(l)(r) 0.35 5.0 200 110 135
82 28 (n)(l)(n) 0.01 5.0 200 110 140 80 29 (n)(l)(n) 0.50 5.0 200
110 130 77 Clad Brazing performance Corrosion resistance Quality of
hot rolled clad material material Joining Generation Fin Breakage
of Melting rate of Average DAS of No. rate Erosion of aperatures
detachment skin material skin material (%) skin material (.mu.m)
Invention 22 .smallcircle. .smallcircle. .smallcircle.
.smallcircle. No <1 4.0 23 .smallcircle. .smallcircle.
.smallcircle. .smallcircle. No <1 4.4 24 x .smallcircle.
.smallcircle. .smallcircle. No <1 4.2 25 .smallcircle. x
.smallcircle. .smallcircle. No <1 3.8 26 .smallcircle.
.smallcircle. x .smallcircle. No <1 4.6 27 .smallcircle.
.smallcircle. .smallcircle. x No <1 4.8 28 .smallcircle.
.smallcircle. .smallcircle. .smallcircle. No <1 3.6 29
.smallcircle. .smallcircle. .smallcircle. .smallcircle. No <1
5.0
[0140] From the result shown in Table 3, it was confirmed that by
using the aluminum alloy of the predetermined composition as a skin
material outstanding brazing performance and corrosion resistance
could be obtained. It was further confirmed that breakage of the
skin material, melting rate of the skin material and average DAS of
the skin material in each clad material were excellent.
Example 3
[0141] This example 3 is an example about an evaluation of the
strength by the core material composition.
[0142] As a skin material 10a and 10b, an ingot manufactured from
the alloy No. (t) in Table 1 by a semi-continuous casting method
was subjected to hot rolling, intermediate annealing at 370.degree.
C..times.4 h, then cold rolling and intermediate annealing if
needed, to thereby obtain a material having a thickness t1 of 0.25
mm.
[0143] About the inventive examples Nos. 30 to 35 shown in Table 4,
using the alloys having compositions (u) to (z) shown in Table 1 as
molten metal M to be used as a core material, a three-layered clad
material 12 in which skin materials 10a and 10b were
pressure-bonded to the both surfaces of the core material 11 using
the aforementioned apparatus 1 for manufacturing a clad material
according to the example 1 was manufactured. In manufacturing, the
target thickness of the core material 11 after the hot roll
cladding was set to 5.0 mm. The contact distance L1 from the
contact starting point P1 to the cooling roller 2a (2b) of the
aforementioned skin material 10a (10b) to the meeting point P2
where the skin material comes into contact with the molten metal M
was set to 200 times of the thickness t1 of skin material 10a
(10b). The remaining conditions were set to the same as in Example
1.
[0144] Subsequently, each heat rolled clad material 12 was
cold-rolled into a thickness of 110 .mu.m, and then subjected to a
heat treatment of 600.degree. C..times.10 min.
[0145] About the clad material after the cold rolling and heat
treatment, the tensile strength at ordinary temperature and the
tensile strength after 180.degree. C..times.10 h holding, the
quality of the hot rolled clad material, the brazing performance,
and the corrosion resistance were measured. These results are shown
in Table 4. TABLE-US-00004 TABLE 4 Hot rolled clad material
Material composition (three layered clad) Cold rolling Clad
Targeted Total thickness Tensile strength material Thickness of the
thickness of of after the cold Heat treatment Normal temp.
180.degree. C. No. Skin/core/skin skin t1 (mm) the core (mm) L1/t1
rolling (.mu.m) Heating conditions strength (MPa) strength (MPa)
Invention 30 (t)(v)(t) 0.25 5.0 200 110 600.degree. C. .times. 10
min 87 53 31 (t)(w)(t) 0.25 5.0 200 110 92 58 32 (t)(x)(t) 0.25 5.0
200 110 143 86 33 (t)(y)(t) 0.25 5.0 200 110 134 81 34 (t)(z)(t)
0.25 5.0 200 110 152 92 35 (t)(u)(t) 0.25 5.0 200 110 65 38 Clad
Brazing performance Corrosion resistance Quality of hot rolled clad
material material Joining Generation Fin Breakage of Melting rate
of Average DAS of No. rate Erosion of apertures detachment skin
material skin material (%) skin material (.mu.m) Invention 30
.smallcircle. .smallcircle. .smallcircle. .smallcircle. No 2 3.8 31
.smallcircle. .smallcircle. .smallcircle. .smallcircle. No 2 4.0 32
.smallcircle. .smallcircle. .smallcircle. .smallcircle. No 3 4.2 33
.smallcircle. .smallcircle. .smallcircle. .smallcircle. No 3 4.8 34
.smallcircle. .smallcircle. .smallcircle. .smallcircle. No 3 4.4 35
.smallcircle. .smallcircle. .smallcircle. .smallcircle. No 2
3.8
[0146] From the result shown in Table 4, it was confirmed that by
using the aluminum alloy of the predetermined composition as a core
material outstanding high temperature strength could be obtained.
Furthermore, it was confirmed that the breakage of the skin
material, the melting rate of the skin material, the average DAS of
the core material, the brazing performance and the corrosion
resistance were excellent.
(Workability)
[0147] About each of the clad materials shown in Table 5 among the
clad materials shown in Tables 2, 3 and 4, the workability was
evaluated based on the formability when the clad material was
formed by roll forming into a fin (20) shape as follows. In cases
where it was formed into a preferable shape, it was noted as
".circleincircle.", in cases where it was formed into a fin shape
although there were variations in fin shape dimension, it was noted
as ".smallcircle.," and in cases where it was impossible to form
into a fin shape due to an occurrence of breakage, it was noted as
"x". TABLE-US-00005 TABLE 5 Clad material No. Workability Inventive
article 1 .circleincircle. 4 .largecircle. Comparative article 11 X
12 X Inventive article 22 .largecircle. 30 .circleincircle. 31
.circleincircle. 32 .largecircle. 33 .largecircle. 34 .largecircle.
35 .circleincircle.
[0148] From the results shown in Table 5, it was confirmed that the
clad materials according to the present invention was superior to
the comparative articles in workability. Furthermore, it was also
confirmed that the inventive articles not exhibited excellent
tensile strength or brazing performance in Tables 2 to 4 were
superior to comparative articles in workability.
[0149] In the above-mentioned Examples 1 to 3, the thickness t1 of
the skin material 10a (10b) was not changed while the skin
materials 10a and 10b were being clad onto the core material 11.
However, the present invention is not limited to it. The present
invention also includes the case in which the thickness of the skin
material decreases due to the cladding by receiving a slight
rolling pressure together with the core material when the skin
materials passes through the cooling rollers 2a and 2b.
INDUSTRIAL APPLICABILITY
[0150] The clad material manufactured by the present invention
includes a core material and skin materials clad on the both
surfaces of the core material, wherein the composition of the skin
material is different from that of the core material. The clad
material can be used for manufacturing metallic material to which
the aforementioned characteristics were given by cladding brazing
material or corrosion resistance material as skin material.
[0151] While the present invention may be embodied in many
different forms, a number of illustrative embodiments are described
herein with the understanding that the present disclosure is to be
considered as providing examples of the principles of the invention
and such examples are not intended to limit the invention to
preferred embodiments described herein and/or illustrated
herein.
[0152] While illustrative embodiments of the invention have been
described herein, the present invention is not limited to the
various preferred embodiments described herein, but includes any
and all embodiments having equivalent elements, modifications,
omissions, combinations (e.g., of aspects across various
embodiments), adaptations and/or alterations as would be
appreciated by those in the art based on the present disclosure.
The limitations in the claims are to be interpreted broadly based
on the language employed in the claims and not limited to examples
described in the present specification or during the prosecution of
the application, which examples are to be construed as
non-exclusive. For example, in the present disclosure, the term
"preferably" is non-exclusive and means "preferably, but not
limited to." In this disclosure and during the prosecution of this
application, means-plus-function or step-plus-function limitations
will only be employed where for a specific claim limitation all of
the following conditions are present in that limitation: a) "means
for" or "step for" is expressly recited; b) a corresponding
function is expressly recited; and c) structure, material or acts
that support that structure are not recited. In this disclosure and
during the prosecution of this application, the terminology
"present invention" or "invention" may be used as a reference to
one or more aspect within the present disclosure. The language
present invention or invention should not be improperly interpreted
as an identification of criticality, should not be improperly
interpreted as applying across all aspects or embodiments (i.e., it
should be understood that the present invention has a number of
aspects and embodiments), and should not be improperly interpreted
as limiting the scope of the application or claims. In this
disclosure and during the prosecution of this application, the
terminology "embodiment" can be used to describe any aspect,
feature, process or step, any combination thereof, and/or any
portion thereof, etc. In some examples, various embodiments may
include overlapping features. In this disclosure and during the
prosecution of this case, the following abbreviated terminology may
be employed: "e.g." which means "for example;" and "NB" which means
"note well."
* * * * *