U.S. patent application number 11/518194 was filed with the patent office on 2007-03-22 for copper alloy and process for producing the same.
Invention is credited to Yasuhiro Maehara, Tsuneaki Nagamichi, Keiji Nakajima, Mitsuharu Yonemura.
Application Number | 20070062619 11/518194 |
Document ID | / |
Family ID | 34975596 |
Filed Date | 2007-03-22 |
United States Patent
Application |
20070062619 |
Kind Code |
A1 |
Maehara; Yasuhiro ; et
al. |
March 22, 2007 |
Copper alloy and process for producing the same
Abstract
A copper alloy that has a specific chemical composition, the
balance being Cu and impurities, in which the relationship between
the total number N and the diameter X satisfies the following
formula (1). This copper alloy is obtained by cooling a bloom, a
slab, a billet or an ingot in at least a temperature range from the
temperature of the bloom, the slab, the billet or the ingot just
after casting to 450.degree. C., at a cooling rate of 0.5.degree.
C./s or more. After the cooling, working in a temperature range of
600.degree. C. or lower and further heat treatment of holding for
30 seconds or more in a temperature range of 150 to 750.degree. C.
are desirably performed. The working and the heat treatment are
most desirably performed for a plurality of times. log
N<0.4742+17.629.times.exp(-0.1133.times.X) (1) wherein N means
the total number of precipitates and inclusions, having a diameter
of not smaller than 1 .mu.m which are found in 1 mm.sup.2 of the
alloy; and X means the diameter in .mu.m of the precipitates and
the inclusions having a diameter of not smaller than 1 .mu.m.
Inventors: |
Maehara; Yasuhiro;
(Kobe-shi, JP) ; Yonemura; Mitsuharu; (Takarazuka
- shi, JP) ; Nakajima; Keiji; (Chuo-ku, JP) ;
Nagamichi; Tsuneaki; (Takarazuka - shi, JP) |
Correspondence
Address: |
CLARK & BRODY
1090 VERMONT AVENUE, NW
SUITE 250
WASHINGTON
DC
20005
US
|
Family ID: |
34975596 |
Appl. No.: |
11/518194 |
Filed: |
September 11, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP05/03502 |
Mar 2, 2005 |
|
|
|
11518194 |
Sep 11, 2006 |
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Current U.S.
Class: |
148/554 ;
148/432 |
Current CPC
Class: |
H01R 13/03 20130101;
C22C 9/10 20130101; C22C 9/00 20130101; C22C 9/06 20130101; H01L
2924/0002 20130101; H01L 2924/0002 20130101; H01L 2924/00
20130101 |
Class at
Publication: |
148/554 ;
148/432 |
International
Class: |
C22C 9/00 20060101
C22C009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 12, 2004 |
JP |
2004-071571 |
Mar 26, 2004 |
JP |
2004-093661 |
Aug 11, 2004 |
JP |
2004-234868 |
Aug 11, 2004 |
JP |
2004-234891 |
Claims
1. A copper alloy characterized in that the alloy consists of, by
mass %, one or more elements selected from Zn, Sn, Ag, Mn, Fe, Co,
Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te and Se of 0.1 to 20%
respectively or in total, and the balance Cu and impurities; and
the alloy satisfies the following formula (1): log
N.ltoreq.0.4742+17.629 exp(-0.1133 X) (1) wherein N means the total
number of precipitates and inclusions, having a diameter of not
smaller than 1 .mu.m, which are found in 1 mm.sup.2 of the alloy;
and X means the diameter in .mu.m of the precipitates and the
inclusions having a diameter of not smaller than 1 .mu.m.
2. A copper alloy characterized in that the alloy consists of, by
mass %, any one element selected from Ti of 0.01 to 5%, Zr of 0.01
to 5% and Hf of 0.01 to 5%, and one or more elements selected from
Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te and Se
of 0.01 to 20% respectively or in total, and the balance Cu and
impurities; and the alloy satisfies the following formula (1): log
N.ltoreq.0.4742+17.629 exp(-0.1133 X) (1) wherein N means the total
number of precipitates and inclusions, having a diameter of not
smaller than 1 .mu.m, which are found in 1 mm.sup.2 of the alloy;
and X means the diameter in .mu.m of the precipitates and the
inclusions having a diameter of not smaller than 1 .mu.m.
3. A copper alloy characterized in that the alloy consists of, in
mass %, Cr of 0.01 to 5%, and one or more elements selected from
Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te and Se
of 0.01 to 20% respectively or in total, and the balance Cu and
impurities; and the alloy satisfies the following formula (1): log
N.ltoreq.0.4742+17.629 exp(-0.1133 X) (1) wherein N means the total
number of precipitates and inclusions, having a diameter of not
smaller than 1 .mu.m, which are found in 1 mm.sup.2 of the alloy;
and X means the diameter in .mu.m of the precipitates and the
inclusions having a diameter of not smaller than 1 .mu.m.
4. A copper alloy according to claim 1, characterized in that the
alloy contains, instead of a part of Cu, one or more elements
selected from Mg, Li, Ca and rare earth elements of 0.001 to 2 mass
% respectively or in total.
5. A copper alloy according to claim 1, characterized in that the
alloy contains, instead of a part of Cu, one or more elements
selected from P, B, Bi, TI, Rb, Cs, Sr, Ba, Tc, Re, Os, Rh, In, Pd,
Po, Sb, Au, Ga, S, Cd, As and Pb of 0.001 to 3 mass % respectively
or in total.
6. A copper alloy according to claim 1, characterized in that the
alloy contains, instead of a part of Cu, Be of 0.1 to 5 mass %.
7. A copper alloy according to claim 1, wherein the ratio of the
"maximum value of an average content" and the "minimum value of an
average content" of at least one alloy element in a micro area is
not smaller than 1.5.
8. A copper alloy according to claim 1, wherein the grain diameter
is 0.01 to 35 .mu.m.
9. A method for producing a copper alloy, comprising cooling a
bloom, a slab, a billet or an ingot obtained by melting a copper
alloy having a chemical composition described in claim 1 followed
by cooling in at least a temperature range from the temperature of
the bloom, the slab, the billet or the ingot just after casting to
450.degree. C. at a cooling rate of 0.5.degree. C./s or more, so
that the relationship between the total number N and the diameter X
satisfies the following formula (1): log N.ltoreq.0.4742+17.629
exp(-0.1 133 X) (1) wherein N means the total number of
precipitates and inclusions, having a diameter of not smaller than
1 .mu.m which are found in 1 mm.sup.2 of the alloy; and X means the
diameter in .mu.m of the precipitates and the inclusions having a
diameter of not smaller than 1 .mu.m.
10. A method for producing a copper alloy, comprising cooling a
bloom, a slab, a billet or an ingot obtained by melting a copper
alloy having a chemical composition described in claim 1 followed
by cooling in at least a temperature range from the temperature of
the bloom, the slab, the billet or the ingot just after casting to
450.degree. C. at a cooling rate of 0.50.degree. C./s or more, and
performing working in a temperature range of 600.degree. C. or
lower, so that the relationship between the total number N and the
diameter X satisfies the following formula (1): log
N.ltoreq.0.4742+17.629 exp(-0.1133 X) (1) wherein N means the total
number of precipitates and inclusions, having a diameter of not
smaller than 1 .mu.m which are found in 1 mm.sup.2 of the alloy;
and X means the diameter in .mu.m of the precipitates and the
inclusions having a diameter of not smaller than 1 .mu.m.
11. A method for producing a copper alloy, comprising cooling a
bloom, a slab, a billet, or a ingot obtained by melting a copper
alloy having a chemical composition described in claim 1 followed
by cooling in at least a temperature range from the temperature of
the bloom, the slab, the billet or the ingot just after casting to
450.degree. C. at a cooling rate of 0.5.degree. C./s or more,
performing working in a temperature range of 600.degree. C. or
lower, and then performing heat treatment of holding for 30 seconds
or more in a temperature range of 150 to 750.degree. C., so that
the relationship between the total number N and the diameter X
satisfies the following formula (1): log N.ltoreq.0.4742+17.629
exp(-0.1133 X) (1) wherein N means the total number of precipitates
and inclusions, having a diameter of not smaller than 1 .mu.m which
are found in 1 mm.sup.2 of the alloy; and X means the diameter in
.mu.m of the precipitates and the inclusions having a diameter of
not smaller than 1 .mu.m.
12. A method for producing a copper alloy according to claim 11,
wherein the working in a temperature range of 600.degree. C. or
lower and the heat treatment of holding for 30 seconds or more in a
temperature range of 150 to 750.degree. C. are performed for a
plurality of times.
13. The method for producing a copper alloy according to claim 1,
wherein the working in a temperature range of 600.degree. C. or
lower is performed after the final heat treatment.
Description
TECHNICAL FIELD
[0001] The present invention relates to a copper alloy, which can
be produced at low cost and has excellent mechanical and electrical
properties. This invention also relates to a process for producing
the said copper alloy. This copper alloy is suitable for electrical
and electronic parts, safety tools, and the like.
[0002] Examples of the electric and electronic parts include
connectors for personal computers, semiconductor plugs, optical
pickups, coaxial connectors, IC checker pins and the like in the
electronics field; cellular phone parts (connector, battery
terminal, antenna part), submarine relay casings, exchanger
connectors and the like in the communication field; and various
electric parts such as relays, various switches, micromotors,
diaphragms, and various terminals in the automotive field; medical
connectors, industrial connectors and the like in the medical and
analytical instrument field; and air conditioners, home appliance
relays, game machine optical pickups, card media connectors and the
like in the electric home appliance field.
[0003] Examples of the safety tools include excavating rods and
tools such as spanner, chain block, hammer, driver, cutting pliers,
and nippers, which are used where a possible spark explosion hazard
may take place, for example, in an ammunition chamber, a coal mine,
or the like.
BACKGROUND ART
[0004] A Cu--Be alloy has been known as a copper alloy that is used
for the above mentioned electric and electronic parts. This alloy
is strengthened by age precipitation of the Be, and contains a
substantial amount of Be. This alloy has been extensively used as a
spring material or the like because it is excellent in both tensile
strength and electric conductivity. However, Be oxide is generated
in the production process of Cu--Be alloy and also in the process
of forming to various parts.
[0005] Be is an environmentally harmful material as is Pb and Cd.
Particularly, the substantial amount of Be in the conventional
Cu--Be alloy necessitates a treatment process for the Be oxide in
the production and working of the copper alloy. The treatment
process leads to an increase in the production cost. It also causes
a problem in the recycling process of the electric and electronic
parts. Thus the Cu--Be alloy is a problematic material from the
environmental point of view. Therefore, a material, which is
excellent in both tensile strength and electric conductivity and in
which the content of environmentally harmful elements such as Be is
as low as possible, is desired.
[0006] A copper alloy called Corson alloy, in which Ni.sub.2Si is
precipitated, is proposed in Patent Document 1. This alloy has a
relatively good balance of tensile strength and electric
conductivity among alloys free from environmentally harmful
elements such as Be, and has a electric conductivity of about 40%
at a tensile strength of 750 to 820 MPa.
[0007] However, this alloy has limitations in enhancing strength
and electric conductivity, and this still leaves a problem from the
point of product variations as described below. This alloy has age
hardenability due to the precipitation of Ni.sub.2Si. If the
electric conductivity is enhanced by reducing the contents of Ni
and Si, the tensile strength is significantly reduced. On the other
hand, even if the contents of Ni and Si are increased in order to
raise the precipitation quantity of Ni.sub.2Si, the electric
conductivity is seriously reduced, although the rise of tensile
strength is limited. Therefore, the balance between tensile
strength and electric conductivity of the Corson alloys is
disrupted in an area with high tensile strength and in an area with
high electric conductivity, consequently narrowing the product
variations. This is explained as follows.
[0008] The electric resistance (or electric conductivity that is
the inverse thereof of an alloy is determined by electron
scattering, and fluctuates depending on the kinds of elements
dissolved in the alloy. Since the Ni dissolved in the alloy
noticeably raises the electric resistance (noticeably reduces the
electric conductivity), the electric conductivity reduces in the
above-mentioned Corson alloy if Ni is increased. On the other hand,
the tensile strength of the copper alloy is obtained due to an age
hardening effect. The tensile strength is improved more as the
quantity of precipitates grows larger, or as the precipitates are
dispersed more finely. The Corson alloy has limitations in
enhancing the strength from the point of the precipitation quantity
and from the point of the dispersing state, since the precipitated
particle is made up of Ni.sub.2Si only.
[0009] Patent Document 2 discloses a copper alloy with a
satisfactory wire bonding property, which contains elements such as
Cr and Zr and has a regulated surface hardness and surface
roughness. As described in an embodiment thereof, this alloy is
produced based on hot rolling and solution treatment.
[0010] However, the hot rolling needs a surface treatment for
preventing hot cracking or removing scales, which result in a
reduction in yield. Further, frequent heating in the atmosphere
facilitates oxidation of active additive elements such as Si, Mg
and Al. Therefore, the generated coarse internal oxides
problematically s cause deterioration of characteristics of the
final product. Further, the hot rolling and solution treatment need
an enormous amount of energy. The copper alloy described in Patent
Document 2 thus has problems in view of an addition in production
cost and energy saving because this alloy is based on the hot
working and solution treatment, Furthermore, deterioration of
product characteristics (bending workability, fatigue
characteristic and the like besides tensile strength and electric
conductivity), which is result of generation of coarse oxides and
the like.
[0011] On the other hand, the safety tool materials have required
mechanical properties, for example, strength and wear resistance
matching those of tool steel. It is also required to avoid
generating sparks which could cause an explosion. In other words,
excellent spark generation resistance is necessary for the safety
tool materials. Therefore, a copper alloy with high thermal
conductivity, particularly, a Cu--Be alloy aimed at strengthening
by age precipitation of Be has been extensively used. Although the
Cu--Be alloy is an environmentally problematic material, as
described above, it has been heavily used as the safety tool
material based on the following.
[0012] FIG. 1 is a graph showing the relationship between electric
conductivity [IACS (%)] and thermal conductivity [TC (W/m.K)] of a
copper alloy. As shown in FIG. 1, both are almost in a
1:1-relation. Enhancing of the electric conductivity [IACS (%)]
means enhancing of the thermal conductivity [TC (W/m.K)], in other
words, enhancing of the electric conductivity inproves the spark
generation resistance. Sparks are generated by the application of a
sudden force by an impact blow or the like during the use of a tool
due to a specified component in the alloy being burnt by the heat
generated by an impact or the like. As described in Non-Patent
Document 1, steel tends to cause a local temperature rise due to
its thermal conductivity which can be as low as 1/5 or less of that
of Cu. Since the steel contains C, a reaction
"C+O.sub.2.fwdarw.CO.sub.2" takes place, generating sparks. In
fact, it is known that pure iron containing no C generates no
sparks. Other metals which tend to generate sparks are Ti and Ti
alloy. The thermal conductivity of Ti is as extremely low, as low
as 1/20 of that of Cu, and therefore the reaction
"Ti+O.sub.2.fwdarw.TiO.sub.2" takes place. Data shown in Non-Patent
Document 2 are summarized in FIG. 1.
[0013] However, the electric conductivity [IACS (%)] and the
tensile strength [TS (MPa)] are in a trade-off relation, and it is
extremely difficult to enhance both simultaneously. Therefore, the
Cu--Be alloy was the only copper alloy that had sufficiently high
thermal conductivity TC while retaining a tool steel-level high
tensile strength in the past.
[Patent Document 1]
[0014] Japanese Patent No. 2,572,042
[Patent Document 2]
[0015] Japanese Patent No. 2,714,561
[Non-Patent Document 1]
[0016] Industrial Heating, Vol. 36, No. 3 (1999), Japan Industrial
Furnace
Manufacturers Association, p. 59
[Non-Patent Document 2]
[0017] Copper and Copper Alloy Product Data Book, Aug. 1, 1997,
issued by Japan Copper and Brass Association, pp. 328-355
[Disclosure of the Invention]
[Subject to be Solved by the Invention]
[0018] It is the primary objective of the present invention to
provide a copper alloy, which is excellent in ductility and
workability with a wide production variations and, further,
excellent in performances required for safety tool materials, such
as thermal conductivity, wear resistance and spark generation
resistance. It is the second objective of the present invention to
provide a method for producing the above-mentioned copper
alloy.
[0019] The "wide production variations" mean that the balance
between electric conductivity and tensile strength can be adjusted
from a high level equal to or higher than that of the Cu--Be alloy
to a low level equal to that of a conventionally known copper
alloy, by minutely adjusting addition quantities and/or a
production condition.
[0020] The "balance between electric conductivity and tensile
strength can be adjusted from a high level equal to or higher than
that of the Cu--Be alloy" specifically means a state satisfying the
following formula (a). This state is hereinafter referred to as a
"state with an extremely satisfactory balance of tensile strength
and electric conductivity". TS
.gtoreq.648.06+985.48.times.exp(-0.0513.times.IACS) (a) wherein TS
represents tensile strength (MPa) and IACS represents electric
conductivity (%).
[0021] For the bending workability, it is also desirable to ensure
a level equal to that of a conventional alloy such as Cu--Be alloy.
Specifically, the bending workability can be evaluated by
performing a 90.degree. C.-bending test to a specimen at various
curvature radiuses, measuring a minimum curvature radius R, never
causing cracking, and determining the ratio B (=R/t) of this radius
to the plate thickness t. A satisfactory range of bending
workability satisfies B.ltoreq.2.0 in a plate material with a
tensile strength TS of 800 MPa or less, which satisfies the
following formula (b) in a plate material having a tensile strength
TS exceeding 800 MPa. B.ltoreq.41.2686-39.4583.times.exp
[-{(TS-615.675)/2358.08}.sup.2] (b)
[0022] For a copper alloy as safety tool, wear resistance is also
required in addition to other characteristics such as tensile
strength TS and electric conductivity IACS as described above.
Therefore, it is necessary to ensure that wear resistance is equal
to that of tool steel. Specifically, a hardness at room temperature
of 250 or more in the Vickers hardness is regarded as excellent
wear resistance.
[Means to solve the Problems]
[0023] The present invention involves copper alloys shown in the
following (A) to (C), and a method for producing a copper alloy
shown in the following (D).
[0024] (A) A copper alloy characterized in that the alloy consists
of, by mass %, one or more elements selected from Zn, Sn, Ag, Mn,
Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W, Ge, Te and Se of 0.1 to 20%
respectively or in total, and the balance Cu and impurities; and
the alloy satisfies the following formula (1): log
N.ltoreq.0.4742+17.629.times.exp(-0.1133.times.X) ) (1)
[0025] wherein N means the total number of precipitates and
inclusions, having a diameter of not smaller than 1 .mu.m, which
are found in 1 mm.sup.2 of the alloy; and X means the diameter in
.mu.m of the precipitates and the inclusions having diameter of not
smaller than 1 .mu.m.
[0026] (B) A copper alloy characterized in that the alloy consists
of, by mass %, an element selected from Ti of 0.01 to 5%, Zr of
0.01 to 5% and Hf of 0.01 to 5%, and one or more elements selected
from Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W. Ge, Te
and Se of 0.01 to 20% respectively or in total, and the balance Cu
and impurities; and the alloy satisfies the following formula (1):
log N.ltoreq.0.4742+17.629.times.exp(-0.1133.times.X) (1)
[0027] wherein N means the total number of precipitates and
inclusions, having a diameter of not smaller than 1 .mu.m, which
are found in 1 mm.sup.2 of the alloy; and X means the diameter in
.mu.m of the precipitates and the inclusions having diameter of not
smaller than 1 .mu.m.
[0028] (C) A copper alloy characterized in that the alloy consists
of, by mass %, Cr of 0.01 to 5%, and one or more elements selected
from Zn, Sn, Ag, Mn, Fe, Co, Al, Ni, Si, Mo, V, Nb, Ta, W. Ge, Te
and Se of 0.01 to 20% respectively or in total, and the balance Cu
and impurities; and the alloy satisfies the following formula (1):
log N.ltoreq.0.4742+17.629.times.exp(-0.1133.times.X) (1)
[0029] wherein N means the total number of precipitates and
inclusions, having a diameter of not smaller than 1 .mu.m, which
are found in 1 mm.sup.2 of the alloy; and X means the diameter in
.mu.m of the precipitates and the inclusions having diameter of not
smaller than 1 .mu.m.
[0030] The copper alloy shown in above (A), (B) or (C) may, instead
of a part of Cu, contain one or more elements selected from Mg, Li,
Ca and rare earth elements of 0.001 to 2 mass % respectively or in
total , and/or one or more elements selected from P, B, Bi, Tl, Rb,
Cs, Sr, Ba, Tc, Re, Os, Rh, In, Pd, Po, Sb, Au, Ga, S, Cd, As and
Pb of 0.001 to 3 mass % respectively or in total. Further the alloy
may contain 0.1 to 5 mass % of Be. In these alloys, it is desirable
that the ratio of the "maximum value of the average content" and
the "minimum value of the average content" of at least one alloy
element in a micro area is not less than 1.5. The grain size of the
alloy is desirably 0.01 to 35 .mu.m.
[0031] (D) A method for producing a copper alloy, which satisfies
the following formula (1), comprising cooling a bloom, a slab, a
billet or an ingot obtained by melting a copper alloy, having a
chemical composition described in the above (A), (B) or (C)
followed by cooling in at least a temperature range from the
temperature of the bloom, the slab, the billet or the ingot just
after casting to 450.degree. C., at a cooling rate of 0.5.degree.
C./s or more, log N.ltoreq.0.4742+17.629.times.exp(-0.1133.times.X)
(1)
[0032] wherein N means the total number of precipitates and
inclusions, having a diameter of not smaller than 1 .mu.m which are
found in 1 mm.sup.2 of the alloy; and X means the diameter in .mu.m
of the precipitates and the inclusions having a diameter of not
smaller than 1 .mu.m.
[0033] After the cooling, working in a temperature range of
600.degree. C. or lower, and a further heat treatment holding for
30 seconds or more in a temperature range of 150 to 750.degree. C.
are desirably performed. The working in a temperature range of
600.degree. C. or lower and the heat treatment of holding in a
temperature range of 150 to 750.degree. C. for 30 seconds or more
may be performed for a plurality of times. After the final heat
treatment, the working in a temperature range of 600.degree. C. or
lower may be performed.
[0034] The precipitates in the present invention mean metals or
compounds of copper and additive elements and between additive
elements, for example, Cu.sub.4Ti in the, alloy containing Ti,
Cu.sub.9Zr.sub.2 in the alloy containing Zr, metal Cr in the alloy
containing Cr. The inclusions mean, for example, metal oxides,
metal carbides, metal nitrides and the like.
[Best Mode for Carrying Out the Invention]
[0035] An embodiment of the present invention will be described in
detail. In the following description, "%" for content of each
element represents "% by mass".
1. Copper Alloy of the Present Invention
(a) Chemical Composition
[0036] One of the copper alloy according to the present invention
has a chemical composition consisting of 0.1 to 20% respectively or
in total of at least one element selected from Zn, Sn, Ag, Mn, Fe,
Co, Al, Ni, Si, Mo, V, Nb, Ta, W. Ge, Te and Se (referred to as
"the first group elements" hereinafter) and the balance Cu and
impurities.
[0037] Each of these elements has an effect of improving corrosion
resistance and heat resistance while keeping a balance between
strength and electric conductivity. This effect is exhibited when
0.1% or more respectively or in total of these elements is
contained. However, when their contents are excessive, the electric
conductivity is reduced. Accordingly, these elements should be
contained at 0.1 to 20% respectively or in total. Particularly,
since Ag and Sn contribute to the increase in strength of the alloy
by forming fine precipitates, active use of them is preferred. In
the alloy that contains the following second group elements, the
lower limit of the first group elements may be 0.01% because the
strength can be maintained the second group elements.
[0038] The copper alloy of the present invention may contain an
element selected from 0.01 to 5% of Ti, 0.01 to 5% of Zr and 0.01
to 5% of Hf, and also may contain 0.01 to 5.0% Cr, instead of a
part of Cu. Hereinafter, these elements are referred to as the
second group elements. An element selected from Ti: 0.01 to 5%, Zr:
0.01 to 5% and Hf 0.01 to 5%
[0039] Since Ti, Zr and Hf increase high-temperature strength of
the alloy, an element selected from them can be contained in the
alloy of the invention. The effect appears remarkably when the
content of the elements is 0.01% or more respectively. However, if
the content exceeds 5%, the electric conductivity is deteriorated
although the strength is enhanced. Further, segregation of these
elements caused in casting makes it difficult to obtain a
homogeneous dispersion of the precipitates, and cracking or
chipping tends to occur in the subsequent working. Therefore, it is
desirable to make the content of these elements 0.01 to 5.0%
respectively when they are added to the alloy. In order to obtain
an extremely satisfactorily balanced state of tensile strength and
electric conductivity, it is desirable to make the alloy contain
0.1% or more of these elements.
Cr: 0.01 to 5%
[0040] Cr is an element that increases strength without making
electric conductivity higher. In order to obtain the effect, the Cr
content is preferably 0.01% or more. Particularly, in order to
obtain an extremely satisfactorily balanced state of tensile
strength and electric conductivity equal to or more than that of
the Cu--Be alloy, a content of 0.1% or more is desirable. On the
other hand, if the Cr content exceeds 5%, coarse metal Cr is formed
so as to adversely affect the bending characteristic, fatigue
characteristic and the like. Therefore, the preferable Cr content
is 0.01 to 5% when it is added.
[0041] For the purpose of increasing high-temperature strength, the
copper alloy of the present invention desirably contains, instead
of a part of Cu, one or more elements selected from Mg, Li, Ca and
rare earth elements of 0.001 to 2% respectively or in total.
Hereinafter these elements are referred to as the third group
elements.
[0042] Mg, Li, Ca and rare earth elements are easily bonded with an
oxygen atom in the Cu matrix, leading to fine dispersion of the
oxides, which enhance the high-temperature strength. This effect is
noticeable when the total content of these elements is 0.001% or
more. However, a content exceeding 2% could result in saturation,
and causes problems such as reduction in electric conductivity and
deterioration of bending workability. Therefore, when one or more
element selected from Mg, Li, Ca and rare earth elements are
included, the respective or total content thereof is desirably set
to 0.001 to 2%. The rare earth elements mean Sc, Y and lanthanide,
may be added separately or in a form of misch metal.
[0043] For the purpose of extending the width (.DELTA.T) between
liquidus and solidus in the casting, the copper alloy of the
present invention desirably includes 0.001 to 0.3% respectively or
in total of one or more elements selected from P. B, Bi, Tl, Rb,
Cs, Sr, Ba, Tc, Re, Os, Rh, In, Pd, Po, Sb, Au, Ga, S, Cd, As and
Pb instead of a part of Cu. However, it is recommendable not to use
As, Pd and Cd because they are detrimental elements. Hereinafter
these elements from P to Pb are referred to as the fourth group
elements. Although .DELTA.T is increased by a so-called
supercooling phenomenon in rapid solidification, .DELTA.T in a
thermally equilibrated state is considered herein as a
standard.
[0044] The above-mentioned elements are effective for lowering the
solidus to extend .DELTA.T. If this width .DELTA.T is extended,
casting is facilitated since a fixed time can be ensured up to
solidification after casting. However, an excessively large
.DELTA.T causes reduction in proof stress in a low-temperature
area, causing cracking at the end of solidification, or so-called
solder brittleness. Therefore, .DELTA.T is preferably set within
the range of 50 to 200.degree. C.
[0045] C, N and O are generally included as impurities. These
elements form carbides, nitrides and oxides with metal elements in
the alloy. These elements may be actively added since the
precipitates or inclusions thereof are effective, if fine, for
strengthening the alloy, particularly, for enhancing
high-temperature strength similarly to the precipitates of metal,
compounds of copper and additive elements or between additive
elements and the like, which are described later. For example, O
has an effect of forming oxides in order to enhance the
high-temperature strength. This effect is easily obtained in an
alloy containing elements which easily form oxides, such as Mg, Li,
Ca and rare earth elements, Al, Si and the like. However, in this
case, a condition in which the solid solution O never remains must
be selected. Care should be taken with residual solid solution
oxygen, since it may cause, in heat treatment under hydrogen a
mosphere, a so-called hydrogen disease of causing a phreatic
explosion as H.sub.2O gas and generate blister or the like, which
deteriorates the quality of the product.
[0046] When the content of each of these elements exceeds 1%, the
precipitates or inclusions thereof are coarse, deteriorating the
ductility. Therefore, each content is preferably limited to 1% or
less, and further preferably to 0.1% or less. content of H is
desirably as small as possible, since H included as an impurity in
the alloy, remains in the state of H.sub.2 gas, which causes
rolling flaw or the like.
[0047] Be is an element that contributes to
precipitation-strengthening without deteriorating electric
conductivity remarkably. In order to obtain the effect, it is
preferable that the content of Be is 0.1 mass % or more. However, a
content exceeding 5% causes not only reduction in electric
conductivity but also reduction of ductility, which deteriorates
workability for rolling or bending and the like. Therefore, the
preferable content of Be is 0.1 to 5% when it is added.
(b) The Total Number of Precipitates and Inclusions
[0048] In the copper alloy of the present invention, the
relationship between the total number N and the diameter X of
precipitates and inclusions that have a diameter of not smaller
than 1 .mu.m satisfies the following formula (1):
log N.ltoreq.0.4742+17.629.times.exp(-0.1133.times.X) (1)
[0049] wherein N means the total number of precipitates and
inclusions, having a diameter of not smaller than 1 .mu.m, which
are found in 1 mm.sup.2 of the alloy; and X means the diameter in
.mu.m of the precipitates and the inclusions having diameter of not
smaller than 1 .mu.m. In the formula (1), X=1 is substituted when
the measured value of the grain size of the precipitates and the
inclusions are 1.0 .mu.m or more and less than 1.5 .mu.m, and
X=.alpha.(.alpha.is an integer of 2 or more) is substituted when
the measured value is ".alpha.-0.5" .mu.m or more and less than
".alpha.+0.5" .mu.m.
[0050] In the copper alloy of the present invention, fine
precipitates of metal, compounds of copper and additive elements
and between additive elements can improve the strength without
reducing the electric conductivity. They enhance the strength by
precipitation hardening. The dissolved Cr, Ti, and Zr are reduced
by precipitation, and the electric conductivity of the copper
matrix comes close to that of pure copper.
[0051] However, when these precipitates and inclusions such as
metal oxides, metal carbides and metal nitrides become coarse with
a diameter of 20 .mu.m or more, the ductility deteriorates, easily
causing cracking or chipping, for example, at the time of bending
or punching for making a connector. It might adversely affect
fatigue characteristic and impact resistance characteristic in use.
Particularly, when a coarse Ti--Cr compound is formed at the time
of cooling after solidification, cracking or chipping tends to
occur in the subsequent working process. Since the hardness is
excessively increased in an aging treatment process, fine
precipitation of said precipitates and inclusions is inhibited, so
that the copper alloy cannot be strengthened. Such a problem is
noticeable when the relationship between the total number of N and
the diameter X does not satisfy the above formula (1).
[0052] In the present invention, therefore, an essential
requirement is regulated so that the relationship between the total
number of N and the diameter X satisfies the above formula (1). The
total number of the precipitates and the inclusions desirably
satisfies the following formula (2), and further preferably
satisfies the following formula (3). The diameter and the total
number of the precipitates and the inclusions can be determined by
using a method shown in Examples. log
N.ltoreq.0.4742+7.9749.times.exp(-0.1133.times.X) (2) log
N.ltoreq.0.4742+6.3579.times.exp(-0.1133.times.X) (3)
[0053] wherein N means the total number of precipitates and
inclusions, having a diameter not smaller than 1 .mu.m which are
found in 1 mm.sup.2 of the alloy; and X means the diameter in .mu.m
of the precipitates and the inclusions having diameter not smaller
than 1 .mu.m. [0054] (c) Ratio of the "Average Content Maximum
Value" to the "Average Content Minimum Value" in Micro-area of at
Least One Alloy eEement.
[0055] The presence of a structure, in which areas with different
concentrations of alloy elements are finely mingled, in the copper
alloy, or the occurrence of a periodic concentration change has an
effect of facilitating acquisition of the micro-crystal grain
structure, since it inhibits minute diffusion of each element and
the grain boundary migration. Consequently, the strength and
ductility of the copper alloy are improved according to the
so-called Hall-Petch law. The micro-area means an area of 0.1 to 1
.mu.m diameter, which substantially corresponds to an irradiation
area in X-ray analysis.
[0056] The areas with different alloy element concentrations in the
present invention are the following two types.
[0057] (1) A state basically having the same fcc structure as Cu,
but having different alloy element concentrations. The lattice
constant is generally differed in spite of the same fcc structure
due to the different alloy element concentrations, and also the
degree of work hardening is of course differed.
[0058] (2) A state where fine precipitates are dispersed in the fcc
matrix. The dispersed state of precipitates after working and heat
treatment is of course differed due to the different alloy element
concentrations.
[0059] The average content in the micro-area means the value in an
analysis area when narrowing to a fixed beam diameter of 1 .mu.m or
less in the X-ray analysis. The value is the average content in
this area. In case of the X-ray analysis, an analyzer having a
field emission type electron gun is desirably used. A desirable
analyzing means are such that have a resolution of 1/5 or less of
the concentration period, and 1/10 is further desirable. If the
analysis area is too large during the concentration period, the
whole is averaged to make the concentration difference difficult to
emerge. Generally, the measurement can be performed by an X-ray
analysis method with a probe diameter of about 1 .mu.m.
[0060] It is the alloy element concentration and fine precipitates
in the matrix that determines the material characteristics.
Therefore, the concentration difference in micro-area including
fine precipitates is questioned in the present invention.
Accordingly, signals from coarse precipitates or coarse inclusions
of 1 .mu.m or more are disturbance factors. However, it is
difficult to perfectly remove the coarse precipitates or coarse
inclusions from an industrial material, and therefore it is
necessary to remove these disturbing factors from the coarse
precipitates and inclusions at the time of analysis. The following
procedure is therefore taken.
[0061] A line analysis is performed using of an X-ray analyzer with
a probe diameter of about 1 .mu.m in order to grasp the periodic
structure of concentration, although it is varied depending on the
materials. An analysis method is determined so that the probe
diameter is about 1/5 of the concentration period or less as
described above. Then a sufficient line analysis length, where the
period emerges about three times or more is determined. The line
analysis is performed m-times (desirably 10 times or more) under
this condition, and the maximum value and the minimum value of
concentration are determined for each of the line analysis
results.
[0062] M pieces each of the resulting maximum values and minimum
values are cut by 20% from the larger value side and averaged. By
the above-mentioned procedure, the disturbing factors due to the
signals from the coarse precipitates and inclusions can be
removed.
[0063] The concentration ratio is determined by the ratio of the
maximum value compared to the minimum value from which the
disturbance factors have been removed. The concentration ratio can
be determined for an alloy element, having a periodic concentration
change of about 1 .mu.m or more, without taking a concentration
change of an atomic level of about 10 nm or less, such as spinodal
decomposition or micro-precipitates, into consideration.
[0064] The reason that the ductility is improved by finely
distributing alloy elements will now be described in detail. When a
concentration change of an alloy element takes place, the
mechanical properties are differed between the high-concentration
part and the low-concentration part, since the degree of
solid-solution hardening of materials and the dispersed state of
precipitates between them are different. During deformation of such
material, the relatively soft part, i.e., low-concentration part is
work-hardened first, and then the deformation of the relatively
hard part, i.e., high-concentration part is started. In other
words, since the work hardening is caused for a plurality of times
as the whole material, high elongation is shown, for example, in
tensile deformation, and also ductility improvement is seen. Thus,
in an alloy where a periodic concentration change of alloy elements
takes place, high ductility advantages for bending work or the like
can be exhibited while keeping the balance between electric
conductivity and tensile strength.
[0065] Since the electric resistance (the inverse of electric
conductivity) mainly responds to a phenomenon in which the electron
transition is reduced due to the scattering of dissolved elements,
and is hardly affected by a macro defect such as grain boundary,
the electric conductivity is never reduced by the above-mentioned
fine grain structure.
[0066] This effect is noticeable when the ratio of the "average
content maximum value" to the "average content minimum value" in
the micro-area of at least one alloy element in the matrix
(hereinafter simply referred to as "concentration ratio") is 1.5 or
more. The upper limit of the concentration ratio is not
particularly determined. However, an excessively high concentration
ratio might cause adverse effects, such that an excessively
increased difference of the electrochemical characteristics which
facilitates local corrosion, and in addition to that the fcc
structure possessed by the Cu alloy cannot be kept. Therefore, the
concentration ratio is set preferably to 20 or less, and more
preferably to 10 or less.
(d) Grain Size
[0067] A finer grain size of the copper alloy is advantageous for
enhancing the strength, and also leads to an improvement in
ductility which improves bending workability and the like. However,
when the grain size is below 0.01 .mu.m, high-temperature strength
may be reduced, and if it exceeds 35 .mu.m, the ductility is
reduced. Therefore, the grain size is desirably set at 0.01 to 35
.mu.m, and further desirably to 0.05 to 30 .mu.m, and most
desirably to 0.1 to 25 .mu.m.
2. Method for Producing a Copper Alloy of the Present Invention
[0068] In the copper alloy of the present invention, inclusions
such as metal oxides, metal carbides and metal nitrides, which
inhibit the fine precipitation of metals, compounds of copper and
additive elements and between additive elements, tend to formed
just after the solidification from the melt. It is difficult to
dissolve such inclusions even if the solution treatment at a higher
temperature is performed after casting. The solution treatment at a
high temperature only causes coagulation and the coarsening of the
precipitates and inclusions.
[0069] Therefore, in the method for producing the copper alloy of
the present invention, a bloom, a slab, a billet or an ingot,
obtained by melting the copper alloy having the above chemical
composition by casting, is cooled to at least a temperature range
from the bloom, the slab, the billet or the ingot temperature just
after casting to 450.degree. C., at a cooling rate of 0.5.degree.
C./s or more, whereby the relationship between the total number N
and the diameter X of the precipitates and the inclusions having
diameter of not smaller than 1 .mu.m satisfies the following
formula (1): log N.ltoreq.0.4742+17.629.times.exp(-0.1133.times.X)
(1)
[0070] wherein N means the total number of precipitates and
inclusions, which are found in 1 mm.sup.2 of the alloy; and X means
the diameter in .mu.m of the precipitates and the inclusions having
diameter of not smaller than 1 .mu.m.
[0071] After the cooling, working in a temperature range of
600.degree. C. or lower, and a holding heat treatment for 30
seconds or more in a temperature range of 150 to 750.degree. C.
after this working are desirably performed. The working in a
temperature range of 600.degree. C. or lower and the holding heat
treatment for 30 seconds or more in a temperature range of 150 to
750.degree. C. are further desirably performed for a plurality of
times. After the final heat treatment, the working may be further
performed. [0072] (a) A cooling rate at least in a temperature
range from the bloom, the slab, the billet or the ingot temperature
just after casting to 450.degree. C.: 0.5.degree. C./s or more
[0073] The precipitates such as metals, compounds of copper and
added elements and between added compounds are formed in a
temperature range of 280.degree. C. or higher. Particularly, when
the cooling rate in a temperature range, from the bloom, the slab,
the billet or the ingot temperature just after casting to
450.degree. C. is low, inclusions such as metal oxides, metal
carbides and metal nitrides are coarsely formed, and the diameter
thereof may reach 20 .mu.m or more, and further hundreds .mu.m.
Further, the said precipitates are also coarsened to 20 .mu.m or
more. In a state where such coarse precipitates and inclusions are
formed, not only cracking or chipping may take place in the
subsequent working, but also a precipitation hardening effect of
the precipitates in an aging process is impaired, so that the alloy
cannot be strengthened. Accordingly, it is needed to cool the
bloom, the slab, the billet or the ingot at a cooling rate of
0.5.degree. C./s or more at least in the said temperature range. A
higher cooling rate is more preferable. The cooling rate is
preferably 2.degree. C./s or more, and more preferably 10.degree.
C./s or more. [0074] (b) Working Temperature After Cooling: A
Temperature Range of 600.degree. C. or Lower
[0075] In the method for producing a copper alloy of the present
invention, the bloom, the slab, the billet or the ingot obtained by
casting is made into a final product, after cooling under a
predetermined condition, only by a combination of working and aging
heat treatment without passing through a hot process, such as hot
rolling or solution treatment.
[0076] A working such as rolling or drawing may be performed at
600.degree. C. or lower. For example, when continuous casting is
adapted, such a working can be performed in the cooling process
after solidification. When the working is performed in a
temperature range exceeding 600.degree. C., precipitates such as
metals, compounds of copper and additive elements and between
additive elements are coarsely formed at the time of working,
deteriorating the ductility, impact resistance, and fatigue
property of the final product. When the above-mentioned
precipitates are coarsened at the time of working, fine
precipitates cannot be formed in the aging treatment, resulting in
an insufficient strengthening of the copper alloy.
[0077] Since the dislocation density in working is raised more as
the working temperature is lower, precipitates such as metals,
compounds of copper and additive elements and between additive
elements can become finer in the subsequent aging treatment.
Therefore, further high strength can be given to the copper alloy.
The working temperature is preferably 450.degree. C. or lower, more
preferably 250.degree. C. or lower, and most preferably 200.degree.
C. or lower. The temperature may also be 25.degree. C. or
lower.
[0078] The working in the above temperature range is desirably
performed at a working rate (section reduction rate) of 20% or
more, and more desirably 50% or more. If the working is performed
at such a working rate, the dislocation introduced thereby can act
as precipitation nuclei at the time of aging treatment, which leads
to fine dispersion of the precipitates and also shortens of the
time required for the precipitation, and therefore the reduction of
dissolved elements harmful to electric conductivity can be early
realized.
(c) Aging Treatment Condition: Holding for 30 Seconds or More in a
Temperature Range of 150 to 750.degree. C.
[0079] The aging treatment is effective for precipitating metals,
compounds of copper and additive elements and between additive
elements in order to strengthen the copper alloy, and also reduce
dissolved elements (Cr, Ti, etc.) harmful to electric conductivity
in order to improve the electric conductivity. However, at a
treatment temperature below 150.degree. C., an excessive amount of
time is required for the diffusion of the precipitated elements,
which reduces the productivity. On the other hand, at a treatment
temperature exceeding 750.degree. C., not only the precipitates are
too coarsened to attain the strengthening by the precipitation
hardening effect, but also the ductility, impact resistance and
fatigue characteristic deteriorates. Therefore, the aging treatment
is desirably performed in a temperature range of 150 to 750.degree.
C. The aging treatment temperature is desirably 200 to 750.degree.
C., further desirably 250 to 650.degree. C., and most desirably 280
to 550.degree. C..
[0080] When the aging treatment time is less than 30 seconds, a
desired precipitation quantity cannot be ensured even if the aging
treatment temperature is high. When the time is longer than 72
hours, production cost becomes higher. Therefore, the aging
treatment in a temperature range of 150 to 750.degree. C. is
desirably performed for 30 seconds or more. The treatment time is
desirably 5 minutes or more, further desirably 10 minutes or more,
and most desirably 15 minutes or more. The upper limit of the
treatment time is not particularly limited. However, 72 hours or
less is desirable from the point of the treatment cost. When the
aging treatment temperature is high, the aging processing time can
be shortened.
[0081] The aging treatment is preferably performed in a reducing
atmosphere, in an inert gas atmosphere, or in a vacuum of 20 Pa or
less in order to prevent the generation of scales due to oxidation
on the surface. Excellent plating property can also be ensured by
the treatment in such an atmosphere.
[0082] The above-mentioned working and aging treatment may be
performed repeatedly as the occasion demands. When the working and
aging treatment are repeatedly performed, a desired precipitation
quantity can be obtained in a shorter time than in the case of one
set treatment (working and aging treatment), and precipitates such
as metals, compounds of copper and additive elements and between
additive elements can be more finely precipitated. For example,
when the treatment is repeated twice, the second aging treatment
temperature is preferably set slightly lower than the first aging
treatment temperature (by 20 to 70.degree. C.). If the second aging
treatment temperature is higher, the precipitates formed in the
first aging treatment are coarsened. On and after the third aging
treatment, the temperature is desirably set lower than the previous
aging treatment temperature. The working in a temperature range of
600.degree. C. or lower may be performed after the final heat
treatment.
(d) Others
[0083] In the method for producing the copper alloy of the present
invention, conditions other than the above production conditions,
for example, conditions for melting, casting and the like are not
particularly limited. These treatments may be performed as
follows.
[0084] Melting is preferably performed in a non-oxidative or
reducing atmosphere. If the dissolved oxygen in a molten copper is
increased, the so-called hydrogen-induced blistering due to
generation of steam is caused in the subsequent process. Further,
coarse oxides of easily-oxidizable dissolved elements such as Ti
and Cr are formed, and if they are left in the final product, the
ductility and fatigue characteristic are seriously reduced.
[0085] In order to obtain the bloom, the slab, the billet or the
ingot, continuous casting is preferably adapted from the point of
productivity and solidification rate. However, any other methods,
which satisfy the above-mentioned conditions, for example, an ingot
method, can be used. The casting temperature is preferably
1250.degree. C. or higher, and further preferably 1350.degree. C.
or higher. At this temperature, Cr, Ti and Zr can be sufficiently
dissolved, and formation of inclusions such as metal oxides, metal
carbide and metal nitrides, precipitates such as metals, compounds
of copper and additive elements and between additive elements can
be prevented.
[0086] When the bloom, the slab or the billet is obtained by the
continuous casting, a method using graphite mold, which is
generally adapted for a copper alloy is recommended from the
viewpoint of lubricating property. As a mold material, a refractory
material, which is hardly reactive with Ti, Cr or Zr that is an
essential alloy element, for example, zirconia may be used.
EXAMPLE 1
[0087] Copper alloys, having chemical compositions shown in Tables
1 to 3 were melted by a vacuum induction furnace, and cast in a
zirconia made mold, whereby slabs 12 mm thick were obtained. Each
of rare earth elements was added alone or in a form of misch metal.
TABLE-US-00001 TABLE 1 Chemical Composition (mass %, Balance: Cu
& Impurities) Alloy 2nd group elements No. 1st group elements
Total Ti Zr Hf Cr 3rd group elements Total 4th group elements Total
Be 1 15Fe, 1.0Si, 0.2Sn, 1.2Al 17.4 0.05 -- -- -- 0.5Y, 0.01Nd,
0.02Ca 0.53 0.001B 0.001 -- 2 10Fe, 2.5Ni, 1.0Si, 0.4Zn 13.9 0.49
-- -- -- -- -- -- -- -- 3 1.01Fe, 0.1Zn 1.11 1.02 -- -- -- 0.02Mg
0.02 -- -- -- 4 0.99Fe, 0.5Ag 1.49 1.51 -- -- -- -- -- 0.01P, 0.1Bi
0.11 -- 5 0.01Sn 0.01 1.93 -- -- -- 0.001La 0.001 0.15Sr, 0.5Pd,
0.1Os 0.75 -- 6* 5.0Zn, 15Fe, 5Co, 2.0Si 27.0* 5.80* -- -- --
0.5Nd, 0.5Gd, 2.0Ca 3.0* 0.5B, 0.6Tc 1.1 -- 7 0.2Ta, 12Co, 1.5Si
13.7 -- 0.07 -- -- 0.2Sc, 0.2Ce 0.4 0.1Tl, 0.5Cs, 0.1Po 0.7 -- 8
2.5Fe, 15.5Nb, 0.1Ge 18.1 -- 0.51 -- -- -- -- -- -- -- 9 0.97Fe,
0.5V, 0.3Mo 1.77 -- 1.02 -- -- 0.01Mg, 0.1Gd 0.11 -- -- -- 10
0.5Fe, 0.5Ta 1.0 -- 1.48 -- -- 0.01Mg 0.01 0.011P, 1.0Ba, 0.1Sb
1.111 -- 11 1.01Fe, 0.1W, 0.1Ag 1.21 -- 2.01 -- -- -- -- 0.012B,
0.1Re, 0.1Tc 0.212 -- 12* 1.5W, 0.5Al, 0.5Ag 2.5 -- 6.10* -- --
0.1La, 0.01Ca 0.11 0.2Sb 0.2 -- 13 0.4Mo, 1.0Co, 15Fe, 0.4Se 16.8
-- -- 0.01 -- 0.1La, 0.01Mg, 0.001Li 0.111 0.1In, 0.5Pd, 0.1Ga 0.7
-- 14 1.0Fe, 0.5Si, 1.0Nb 2.5 -- -- 0.52 -- -- -- -- -- -- 15
0.98Fe, 0.2Mo, 0.4Zn 1.58 -- -- 0.99 -- 0.01Li 0.01 -- -- -- 16
0.99Fe 0.99 -- -- 1.48 -- 0.01Ca 0.01 0.010P, 0.02B 0.03 -- 17
0.4Si, 0.3Sn, 1.2V 1.9 -- -- 2.01 -- -- -- 0.1Sr, 0.2Re 0.3 -- 18*
0.5Fe, 1.0Co, 0.4Sn 1.9 -- -- 6.20* -- 0.01Sc, 0.1Mg 0.11 0.9Bi,
0.1P 1.0 -- 19 10V, 2.2Co, 0.4Ta, 0.4Mn, 1.0Sn 14.0 -- -- -- 0.05
0.01La 0.01 0.1Rh, 0.01P 0.11 -- 20 2.01Fe, 0.2Mo, 0.5Nb 2.71 -- --
-- 0.50 -- -- -- -- -- 21 1.0Ni, 0.5Si, 0.4Sn 1.9 -- -- -- 0.99
0.02Ca 0.02 -- -- -- 22 0.99Fe 0.99 -- -- -- 1.49 0.01Li, 0.03Ca
0.04 0.011P, 1.0Bi 1.011 -- 23 1.0Fe, 0.5Sn 1.5 -- -- -- 1.99 -- --
0.01B, 0.5Ba, 0.5Sb 1.01 -- 24 12V, 15Fe, 0.5Mo, 1.0Si, 1.0Sn 29.5*
-- -- -- 6.50* 0.1Sc, 0.01Mg 0.11 0.1Au, 0.01Po, 0.1Cs 0.21 -- 25*
0.99Co, 1.02Fe, 0.4Sn 2.41 1.45 -- -- -- 0.5Ca, 0.8Li, 1.5Mg 2.8*
0.001B 0.001 -- *Out of the range regulated by the present
invention.
[0088] TABLE-US-00002 TABLE 2 Chemical Composition (mass %,
Balance: Cu & Impurities) Alloy 2nd group elements No. 1st
group elements Total Ti Zr Hf Cr 3rd group elements Total 4th group
elements Total Be 26 1.01Nb 1.01 1.32 -- -- -- -- -- -- -- -- 27
0.99Co 0.99 1.22 -- -- -- 0.01Mg 0.01 -- -- -- 28 0.98Fe 0.98 1.52
-- -- -- 0.01Mg 0.01 0.008P, 0.01B 0.018 -- 29 0.5V, 0.2Ag 0.7 1.98
-- -- -- -- -- 0.009Bi 0.009 -- 30* 12.5Ni, 5.1Si, 5.6Nb 23.2* 1.55
-- -- -- 1.5Mg, 1.0La 2.5* 0.5In, 1.5Ba, 1.0Os 3.0* -- 31 0.95Co
0.95 -- 1.11 -- -- -- -- 0.001S 0.001 -- 32 1.00Nb 1.00 -- 1.48 --
-- 0.1La, 1.5Ca 1.6 -- -- -- 33 0.99Fe 0.99 -- 1.49 -- -- 0.1Mg,
0.5Nd, 0.8Li 1.4 0.01Cs, 0.03Bi 0.04 -- 34 0.98Co 0.98 -- 1.52 --
-- -- -- 0.01P 0.01 -- 35* 1.1V 1.1 -- 1.32 -- -- 0.1La, 1.5Rh,
2.0Ce 3.6* 1.0Ba, 1.3Po, 2.0Rh 4.3* -- 36 0.99V, 0.24Si 1.23 -- --
1.52 -- -- -- 0.01Bi, 0.02Ba, 0.001P 0.031 -- 37 1.01Co, 2.3Fe,
0.4Sn 3.71 -- -- 1.48 -- -- -- -- -- -- 38 1.1Nb, 0.3Sn, 1.2Ni 2.6
-- -- 1.22 -- 0.01Li, 0.03Gd 0.04 -- -- -- 39* 10.0Co, 10.2Fe,
0.5Si, 26.0* -- -- 1.38 -- 0.01Ca, 0.1Sc 0.11 0.009P 0.009 -- 4.3W,
1.0Mo 40 0.99Co, 0.1Si 1.01 -- -- -- 1.32 -- -- -- -- -- 41*
0.99Nb, 0.1Ge 1.01 -- -- -- 1.42 0.1Ce, 0.01Y 0.11 0.5Sb, 1.5Ba,
1.0Bi 3.0* -- 42* 1.01V, 0.1Al, 0.2Ni 1.31 -- -- -- 1.48 0.01Mg
0.01 1.5Rb, 1.0Pd 2.5* -- 43 1.00Mo, 0.4Zn 1.40 -- -- -- 1.35 -- --
0.012P 0.012 -- 44 1.54Co, 0.8Al 2.34 -- -- -- -- 0.01Nd, 0.05Sc
0.06 -- -- -- 45 0.99Nb, 0.4Mn 1.39 -- -- -- -- -- -- 0.01B 0.01 --
46 1.52Fe, 0.4Te 1.92 -- -- -- -- 0.01Mg, 0.05Y, 0.001Li 0.061
0.011Pd, 0.1Re 0.11 -- 47 2.01Fe, 0.4Zn 2.41 -- -- -- -- -- -- --
-- -- 48* 8.0Nb, 4.0Si, 5.2Ta 17.2 -- -- -- -- 0.7La, 0.5Ca, 1.2Sc
2.4* -- -- -- 49 14Ni, 4Si, 1Ag 19 -- -- -- -- 0.01Nd, 0.05Y 0.06
-- -- -- 50 5.2Mo, 3.1V 8.3 -- -- -- -- -- -- 0.01P, 0.1Ba 0.11 --
*Out of the range regulated by the present invention.
[0089] TABLE-US-00003 TABLE 3 Chemical Composition (mass %,
Balance: Cu & Impurities) Alloy 2nd group elements No. 1st
group elements Total Ti Zr Hf Cr 3rd group elements Total 4th group
elements Total Be 51 10.1W, 4.2Ge 14.3 -- -- -- -- 0.1Ce, 0.01La
0.11 0.1Sr, 0.1Os 0.2 -- 52 2.5Co 2.5 -- -- -- -- 0.01Mg 0.01 -- --
-- 53 1.54Fe 1.54 -- -- -- -- -- -- 0.001B 0.001 -- 54 1.24V 1.24
-- -- -- -- 0.001Li 0.001 0.01Bi 0.01 -- 55* 10.2Fe, 7.8Co, 3.4Zn,
28.4* -- -- -- -- -- -- -- -- -- 3.2Al, 3.8W 56 0.5Fe, 0.5Co, 0.5Ag
1.5 3.00 -- -- -- -- -- 0.1Ba, 0.01Os 0.11 -- 57 0.4Sn, 1.0Fe 1.4
4.00 -- -- -- 0.1Sc, 0.1Ca 0.2 -- -- -- 58 0.25Ta, 0.3Nb 0.55 --
2.50 -- -- 0.01Nd, 0.1La 0.11 0.1Pd, 0.05Bi 0.15 -- 59 0.5Mo, 0.1Fe
0.6 -- 4.00 -- -- -- -- 0.01P, 0.1Re 0.11 -- 60 0.5Fe, 0.1Si, 0.2Sn
0.8 1.50 -- -- -- 0.2Ca 0.2 0.01P, 0.1S 0.11 -- 61 0.6Ag, 4.0Co 4.6
-- -- -- -- -- -- -- -- 0.4 62 1.0Zn, 1.0Ag, 3.0Nb 5.0 -- -- -- --
0.5Mg, 0.1Gd 0.6 -- -- 2.1 63 2.0Fe, 0.5Ta 2.5 -- -- -- -- -- --
0.1P, 0.01B 0.11 0.5 64 0.4Ag 0.4 -- -- -- 2.50 -- -- -- -- 2.1 65
1.0Sn, 2.5Fe, 3.0Se 6.5 -- -- -- -- 0.01Nd 0.01 0.25B, 0.001Tl
0.251 0.6 66 2.0Sn, 0.1Al, 0.1Si 2.2 -- 0.01 -- 2.50 0.1Y, 0.5Sc
0.6 0.5Sb 0.5 2.3 67 0.2Sn, 0.4Te 0.6 0.50 -- -- -- 0.1Ca 0.1
0.01P, 0.1B, 0.001Ga 0.111 2.8 68 0.1Ag, 0.3Fe, 0.5Mo, 0.2Se 1.1
0.20 0.20 -- -- -- -- -- -- 0.6 69 0.5Sn, 0.1Ag 0.6 1.00 2.00 -- --
-- -- 0.3B, 0.1Re, 0.2Rh 0.6 2.8 70 0.5Ta 0.5 -- 0.30 -- -- 0.1Gd
0.1 -- -- 2.6 *Out of the range regulated by the present
invention.
[0090] Each of the resulting slabs was cooled from a temperature
between 950.degree. C. and 450.degree. C., which is the temperature
just after casting (the temperature just after taken out of the
mold), by water spray. The temperature change of the mold in a
predetermined place was measured by a thermocouple buried in the
mold, and the surface temperature of the slab, after leaving the
mold, was measured in several areas by a contact type thermometer.
The average cooling rate, in the temperature range to 450.degree.
C., of the slab surface was calculated by using the above measuring
results and a thermal conduction analysis. In another small scale
experiment, the solidification starting point was determined by
using 0.2 g of a melt of each alloy, and thermally analyzing it
during continuous cooling at a predetermined rate.
[0091] A plate for subsequent rolling with 10 mm thickness .times.8
Omm width .times.150 mm length was prepared from each resulting
slab by cutting and machining. For comparison, a part of the plate
was subjected to a solution heat treatment at 950.degree. C.. The
plates were rolled to 2 mm thick sheets by a reduction of 80% at a
room temperature (first rolling), and further subjected to aging
treatment under a predetermined condition (first aging). A part of
the specimens were further subjected to rolling by a reduction of
95% into 0.1 mm thickness at room temperature (second rolling), and
then subjected to aging treatment under a predetermined condition
(second aging). The production conditions thereof are shown in
Tables 4 to 7.
[0092] For the thus-produced specimens, the diameter and the total
number per unit area of the precipitates and the inclusions,
tensile strength, electric conductivity and bending workability
were measured by the following methods. These results are also
shown in Tables 4 to 7.
.ltoreq.Total Number of Precipitates and Inclusions>
[0093] A section parallel to the rolling plane and that
perpendicular to the transverse direction of each specimen ware
polish-finished, and a visual field of 1mm.times.1mm was observed
by an optical microscope at 100-fold magnification after being
etched with an ammonia aqueous solution. Thereafter, the long
diameter (the length of a straight line which can be drawn longest
within a grain, without contacting the grain boundary halfway) of
the precipitates and the inclusions was measured, and the resulting
value is determined as grain diameter. When the measured value of
the grain diameter of the precipitates and the inclusions is 1.0
.mu.m or more and less than 1.5 .mu.m, X=1 is substituted to the
formula (1), and when the measured value is ".alpha.-0.5" .mu.m or
more and less than ".alpha.+0.5" .mu.m, X=.alpha.(.alpha.is an
integer of 2 or more) can be substituted. Further, the total number
n.sub.1 is calculated by taking one crossing of the frame line of a
visual field of 1mm.times.1 mm as 1/2 and one located within the
frame line as 1 for every grain diameter, and an average "N/10" of
the number of the precipitates and the inclusions N
(=n.sub.1+n.sub.2 +. . . +n.sub.10) in an optionally selected 10
visual fields is defined as the total number of the precipitates
and the inclusions for each grain diameter of the sample.
.ltoreq.Content Ratio>
[0094] A section of the alloy was polished and analyzed at random
10 times for a length of 50 .mu.m by an X-ray analysis at 2000-fold
magnification in order to determine the maximum values and minimum
values of each alloy content in the respective line analyses.
Averages of the maximum value and the minimum value were determined
for eight values each after removing the two larger ones
respectively from the determined maximum values and minimum values,
and the ratio thereof was calculated as the content ratio.
.ltoreq.Tensile Strength>
[0095] A specimen 13B regulated in JIS Z 2201 was prepared from the
above-mentioned specimen so that the tensile direction is parallel
to the rolling direction, and according to the method regulated in
JIS Z 2241, tensile strength [TS (MPa)] at room temperature
(25.degree. C.) thereof was determined.
.ltoreq.Electric Conductivity>
[0096] A specimen of 10 mm width .times.60 mm length was prepared
from the above-mentioned specimen so that the longitudinal
direction is parallel to the rolling direction, and the potential
difference between both ends of the specimen was measured by
applying current in the longitudinal direction of the specimen, and
the electric resistance was determined therefrom by a 4-terminal
method. Successively, the electric resistance (resistivity) per
unit volume was calculated from the volume of the specimen measured
by a micrometer, and the electric conductivity [IACS (%)] was
determined from the ratio to resistivity 1.72 .mu..OMEGA..cndot.cm
of a standard sample obtained by annealing a polycrystalline pure
copper.
.ltoreq.Bending Workability>
[0097] A plurality of specimens of 10 mm width .times.60 mm length
were prepared from the above-mentioned specimen, and a 90.degree.
C. bending test was carried out while changing the curvature radius
(inside diameter) of the bent part. After the test the bent parts
of the specimens were observed from the outer diameter side by use
of an optical microscope. A minimum curvature radius free from
cracking was taken as R, and the ratio B(=R/t) of R to the
thickness t of specimen was determined. TABLE-US-00004 TABLE 4
Production Condition Cooling 1st Rolling 1st Heat Treatment 2nd
Rolling 2nd Heat Treatment Alloy Rate Temp. Thickness Temp. Temp.
Thickness Temp. Division No. (.degree. C./s) (.degree. C.) (mm)
(.degree. C.) Time (.degree. C.) (mm) (.degree. C.) Time Examples
of The 1 1 9 25 2.0 400 2 h 25 0.1 350 10 h Present Invention 2 2
10 25 2.0 400 2 h 25 0.1 350 10 h 3 3 10 25 2.0 400 2 h 25 0.1 350
10 h 4 4 11 25 2.0 400 2 h 25 0.1 350 10 h 5 5 11 25 2.0 400 3 h 25
0.1 350 10 h 6 7 10 25 2.1 400 2 h 25 0.1 350 10 h 7 8 10 25 1.9
400 2 h 25 0.1 350 10 h 8 9 11 25 2.0 400 2 h 25 0.1 350 10 h 9 10
10 25 2.0 400 2 h 25 0.1 350 10 h 10 11 10 25 2.0 400 3 h 25 0.1
350 10 h 11 13 10 25 2.0 400 2 h 25 0.1 350 10 h 12 14 10 25 1.9
400 2 h 25 0.1 350 10 h 13 15 11 25 2.0 400 2 h 25 0.1 350 10 h 14
16 9 25 1.9 400 2 h 25 0.1 350 10 h 15 17 9 25 1.9 400 3 h 25 0.1
350 10 h 16 19 11 25 2.0 400 2 h 25 0.1 350 10 h 17 20 11 25 2.0
400 2 h 25 0.1 350 10 h 18 21 10 25 2.0 400 2 h 25 0.1 350 10 h 19
22 10 25 2.0 400 2 h 25 0.1 350 10 h 20 23 10 25 2.0 400 2 h 25 0.1
350 10 h 21 24 10 25 2.0 400 2 h 25 0.1 350 10 h 22 26 10 25 2.0
400 2 h 25 0.1 350 10 h 23 27 10 25 2.0 400 2 h 25 0.1 350 10 h 24
28 9 25 2.0 400 2 h 25 0.1 350 10 h 25 29 11 25 2.0 400 2 h 25 0.1
350 10 h Characteristics Grain Tensile Bending Workability Size
Strength Conductivity B Division {circle around (1)} {circle around
(2)} (.mu.m) (MPa) (%) (R/t) Evaluation Examples of The 1 .DELTA.
10.5(Fe) 30 905 23 2 .largecircle. Present Invention 2
.circleincircle. 10(Fe), 1.5(Si) 14 1020 26 2 .largecircle. 3
.circleincircle. 3.2(Ti) 10 1169 17 2 .largecircle. 4
.circleincircle. 2.5(Ti) 8 1301 10 3 .largecircle. 5 .largecircle.
3.1(Ti) 0.1 1409 6 5 .largecircle. 6 .DELTA. 2.4(Si) 20 910 21 2
.largecircle. 7 .circleincircle. 12(Nb), 2.5(Fe) 25 1019 26 2
.largecircle. 8 .circleincircle. 1.8(Zr) 15 1173 16 3 .largecircle.
9 .circleincircle. 2.5(Zr) 8 1295 10 5 .largecircle. 10
.largecircle. 5.6(Zr) 1 1439 4 5 .largecircle. 11 .DELTA. 5.2(Fe)
30 890 25 2 .largecircle. 12 .circleincircle. 1.5(Nb), 1.2(Fe) 16
1050 25 2 .largecircle. 13 .circleincircle. 1.8(Fe), 1.5(Zn) 12
1172 17 3 .largecircle. 14 .circleincircle. 1.8(Hf) 5 1293 11 5
.largecircle. 15 .largecircle. 2.8(Hf) 0.2 1439 5 5 .largecircle.
16 .DELTA. 12.5(V) 16 900 25 1 .largecircle. 17 .circleincircle.
3.9(Ti) 33 782 54 1 .largecircle. 18 .circleincircle. 2.3(Ni),
1.5(Si) 35 780 55 1 .largecircle. 19 .circleincircle. 1.8(Fe) 28
865 40 2 .largecircle. 20 .circleincircle. 1.9(Fe) 19 954 30 2
.largecircle. 21 .circleincircle. 11.9(V) 12 1000 22 2
.largecircle. 22 .circleincircle. 5.9(Ti) 10 1230 15 2
.largecircle. 23 .circleincircle. 3.5(Ti), 1.5(Co) 9 1209 18 3
.largecircle. 24 .circleincircle. 3.8(Ti), 1.6(Fe) 10 1290 10 3
.largecircle. 25 .largecircle. 5.2(Ti), 1.5(Ag) 0.5 1405 6 5
.largecircle. "h" in "Time" means hour. ".DELTA.", ".largecircle."
and ".circleincircle." in {circle around (1)} mean that formulas
(1), (2) and (3) are satisfied, respectively. {circle around (2)}
means "content maximum value/content minimum value". Object element
is shown in parentheses. ".largecircle." in "Bending Workability"
means that formula (b) is satisfied.
[0098] TABLE-US-00005 TABLE 5 Production Condition Cooling 1st
Rolling 1st Heat Treatment 2nd Rolling 2nd Heat Treatment Alloy
Rate Temp. Thickness Temp. Temp. Thickness Temp. Division No.
(.degree. C./s) (.degree. C.) (mm) (.degree. C.) Time (.degree. C.)
(mm) (.degree. C.) Time Examples of The 26 31 9 25 2.0 400 2 h 25
0.1 350 10 h Present Invention 27 32 10 25 1.9 400 2 h 25 0.1 350
10 h 28 33 10 25 2.0 400 2 h 25 0.1 350 10 h 29 34 10 25 2.0 400 2
h 25 0.1 350 10 h 30 36 11 25 2.0 400 2 h 25 0.1 350 10 h 31 37 10
25 2.0 400 2 h 25 0.1 350 10 h 32 38 9 25 1.9 400 2 h 25 0.1 350 10
h 33 40 10 25 2.0 400 2 h 25 0.1 350 10 h 34 43 9 25 2.0 400 2 h 25
0.1 350 10 h 35 44 10 25 2.0 400 2 h 25 0.1 350 10 h 36 45 10 25
2.0 400 2 h 25 0.1 350 10 h 37 46 9 25 2.0 400 2 h 25 0.1 350 10 h
38 47 10 25 2.0 400 2 h 25 0.1 350 10 h 39 49 10 25 2.0 400 2 h 25
0.1 350 10 h 40 50 9 25 2.0 400 2 h 25 0.1 350 10 h 41 51 9 25 2.0
400 2 h 25 0.1 350 10 h 42 52 10 25 2.0 400 2 h 25 0.1 350 10 h 43
53 11 25 2.0 400 2 h 25 0.1 350 10 h 44 54 11 25 2.0 400 2 h 25 0.1
350 10 h 45 56 9 25 2.0 400 2 h 25 0.1 350 10 h 46 57 10 25 2.0 400
2 h 25 0.1 350 10 h 47 58 9 25 2.0 400 2 h 25 0.1 350 10 h 48 59 9
25 2.0 400 2 h 25 0.1 350 10 h 49 60 10 25 2.0 400 2 h 25 0.1 350
10 h 50 61 9 25 2.0 400 2 h 25 0.1 350 8 h Characteristics Grain
Tensile Bending Workability Size Strength Conductivity B Division
{circle around (1)} {circle around (2)} (.mu.m) (MPa) (%) (R/t)
Evaluation Examples of The 26 .circleincircle. 1.7(Zr) 10 1240 15 2
.largecircle. Present Invention 27 .circleincircle. 2.1(Zr) 2 1302
10 3 .largecircle. 28 .circleincircle. 2.2(Zr) 4 1298 11 2
.largecircle. 29 .circleincircle. 2.5(Zr) 2 1300 10 3 .largecircle.
30 .circleincircle. 2.0(Zr) 2 1290 10 3 .largecircle. 31
.circleincircle. 13.0(Hf) 5 1230 15 3 .largecircle. 32
.circleincircle. 2.9(Hf) 12 1190 15 2 .largecircle. 33
.circleincircle. 2.5(Hf) 28 800 60 1 .largecircle. 34 .DELTA.
3.5(Cr) 27 815 30 1 .largecircle. 35 .circleincircle. 5.2(Co),
1.5(Al) 15 1005 35 1 .largecircle. 36 .DELTA. 1.5(Nb) 25 836 26 1
.largecircle. 37 .DELTA. 12.6(Fe) 24 928 18 1 .largecircle. 38
.circleincircle. 3.2(Fe) 12 1014 21 2 .largecircle. 39 .DELTA.
5.2(Ni), 2.4(Si) 8 1220 10 3 .largecircle. 40 .circleincircle.
15.2(Mo), 7.8(V) 12 1198 26 2 .largecircle. 41 .DELTA. 21(W),
1.8(Ge) 2 1320 5 4 .largecircle. 42 .circleincircle. 5.8(Co) 10
1030 29 3 .largecircle. 43 .circleincircle. 2.8(Fe) 20 862 40 1
.largecircle. 44 .circleincircle. 5.2(Co), 2.5(Al) 21 810 49 1
.largecircle. 45 .circleincircle. 5.2(Ti) 1 1310 12 4 .largecircle.
46 .largecircle. 10.2(Ti) 0.5 1456 8 5 .largecircle. 47
.largecircle. 5.2(Zr) 0.1 1325 15 4 .largecircle. 48 .largecircle.
8.2(Zr) 0.3 1485 6 5 .largecircle. 49 .largecircle. 3.0(Ti) 5 1100
23 2 .largecircle. 50 .circleincircle. 3.2(Co) 20 820 40 1
.largecircle. "h" in "Time" means hour. ".DELTA.", ".largecircle."
and ".circleincircle." in {circle around (1)} mean that formulas
(1), (2) and (3) are satisfied, respectively. {circle around (2)}
means "content maximum value/content minimum value". Object element
is shown in parentheses. ".largecircle." in "Bending Workability"
means that formula (b) is satisfied.
[0099] TABLE-US-00006 TABLE 6 Production Condition Cooling 1st
Rolling 1st Heat Treatment 2nd Rolling 2nd Heat Treatment 3rd
Rolling Alloy Rate Temp. Thickness Temp. Temp. Thickness Temp.
Temp. Thickness Division No. (.degree. C./s) (.degree. C.) (mm)
(.degree. C.) Time (.degree. C.) (mm) (.degree. C.) Time (.degree.
C.) (mm) 51 62 10 25 2.0 400 2 h 25 0.1 350 8 h -- -- 52 63 10 25
2.0 400 2 h 25 0.1 350 8 h -- -- 53 64 10 25 2.0 400 2 h 25 0.1 350
8 h -- -- 54 65 10 25 2.0 400 2 h 25 0.1 350 8 h -- -- 55 66 10 25
2.0 400 2 h 25 0.1 350 8 h -- -- 56 67 10 25 2.0 400 2 h 25 0.1 350
8 h -- -- 57 68 10 25 2.0 400 2 h 25 0.1 350 8 h -- -- 58 69 10 25
2.0 400 2 h 25 0.1 350 8 h -- -- 59 70 10 25 2.0 400 2 h 25 0.1 350
8 h -- -- 60 3 10 580 3.0 -- -- 25 1.0 450 1.5 h 25 0.1 61 3 10 250
3.0 700 0.5 h 25 1.0 450 1.5 h 25 0.1 62 3 10 580 3.0 600 1 h 25
1.0 450 1.5 h 25 0.1 63 3 10 250 3.0 -- -- 25 1.0 450 1.5 h 25 0.1
64 4 10 500 3.0 -- -- 25 1.0 450 1.5 h 25 0.1 65 4 10 200 3.0 700
0.5 h 25 1.0 450 1.5 h 25 0.1 66 4 10 500 3.0 600 1 h 25 1.0 450
1.5 h 25 0.1 67 4 10 250 3.0 -- -- 25 1.0 450 1.5 h 25 0.1
Production Condition Characteristics 3rd Heat Treatment Grain
Tensile Bending Workability Temp. Size Strength Conductivity B
Division (.degree. C.) Time {circle around (1)} {circle around (2)}
(.mu.m) (MPa) (%) (R/t) Evaluation 51 -- -- .circleincircle.
10.2(Nb), 1.5(Zn) 15 1160 17 2 .largecircle. 52 -- --
.circleincircle. 2.5(Fe) 25 840 40 1 .largecircle. 53 -- --
.circleincircle. 5.9(Cr) 12 1156 17 3 .largecircle. 54 -- --
.circleincircle. 4.8(Fe) 22 870 38 1 .largecircle. 55 -- --
.circleincircle. 1.5(Sn) 3 1200 16 2 .largecircle. 56 -- --
.circleincircle. 1.5(Be) 0.5 1350 14 4 .largecircle. 57 -- --
.circleincircle. 1.5(Be), 1.5(Fe) 14 1000 29 1 .largecircle. 58 --
-- .largecircle. 1.8(Zr) 0.01 1530 12 5 .largecircle. 59 -- --
.largecircle. 5.4(Be) 0.05 1500 12 5 .largecircle. 60 350 5 h
.circleincircle. 2.5(Ti) 15 1040 20 1 .largecircle. 61 350 5 h
.circleincircle. 2.3(Ti) 7 1050 21 1 .largecircle. 62 350 5 h
.circleincircle. 2.5(Ti) 6 1060 22 1 .largecircle. 63 350 5 h
.circleincircle. 3.0(Ti) 13 1100 18 1 .largecircle. 64 350 5 h
.circleincircle. 2.7(Ti) 12 1090 12 1 .largecircle. 65 350 5 h
.circleincircle. 2.5(Ti) 6 1110 13 1 .largecircle. 66 350 5 h
.circleincircle. 2.8(Ti) 5 1100 11 1 .largecircle. 67 350 5 h
.circleincircle. 3.2(Ti) 12 1150 14 1 .largecircle. "h" in "Time"
means hour. ".largecircle." and ".circleincircle." in {circle
around (1)} mean that formulas (1), (2) and (3) are satisfied,
respectively. {circle around (2)} means "content maximum
value/content minimum value". Object element is shown in
parentheses. ".largecircle." in "Bending Workability" means that
formula (b) is satisfied.
[0100] TABLE-US-00007 TABLE 7 Production Condition Cooling 1st
Rolling 1st Heat Treatment 2nd Rolling 2nd Heat Treatment Alloy
Rate Temp. Thickness Temp. Temp. Thickness Temp. Division No.
(.degree. C./s) (.degree. C.) (mm) (.degree. C.) Time (.degree. C.)
(mm) (.degree. C.) Time Comparative 1 6* 11 25 2.0 -- -- -- -- --
-- Examples 2 12* 10 25 2.0 -- -- -- -- -- -- 3 18* 10 25 1.9 -- --
-- -- -- -- 4 25* 10 25 1.9 400 2 h 25 0.1 350 10 h 5 26 10 25 2.0
400 2 h 25 0.1 350 10 h 6 30* 10 25 2.0 400 2 h 25 0.1 350 10 h 7
33 0.3* 25 2.0 400 2 h 25 0.1 350 10 h 8 33 10 800* 2.0 400 2 h 25
0.1 -- -- 9 34 10 25 2.0 400 2 h 25 0.1 350 10 h 10 35* 10 25 2.0
400 2 h 25 0.1 350 10 h 11 37 10 25 2.0 400 2 h 25 0.1 350 10 h 12
39* 10 25 2.0 400 2 h 25 0.1 350 10 h 13 41* 9 25 1.9 400 2 h 25
0.1 350 10 h 14 42* 9 25 2.0 400 2 h 25 0.1 350 10 h 15 43 9 25 2.0
400 2 h 25 0.1 350 10 h 16 48* 10 25 2.0 400 2 h 25 0.1 350 10 h 17
55* 10 25 2.0 -- -- -- -- -- -- Characteristics Grain Tensile
Bending Workability Size Strength Conductivity B Division {circle
around (1)} {circle around (2)} (.mu.m) (MPa) (%) (R/t) Evaluation
Comparative 1 -- -- -- -- -- -- -- Examples 2 -- -- -- -- -- -- --
3 -- -- -- -- -- -- -- 4 X -- 9 1250 5 6 X 5 X 0.1(Ti) 25 750 25 6
X 6 X -- 3 1310 2 7 X 7 X -- 4 720 20 5 X 8 -- -- -- -- -- -- -- 9
X 0.05(Zr) 32 720 34 5 X 10 X -- 8 1110 8 5 X 11 X 0.11(Hf) 28 690
38 4 X 12 X -- 10 1210 5 6 X 13 X -- 26 820 22 4 X 14 X -- 26 873
20 4 X 15 X 0.9(Mo) 35 692 46 5 X 16 X -- 10 1200 2 6 X 17 -- -- --
-- -- -- -- "h" in "Time" means hour. "X" in {circle around (1)}
means that formulas (1), (2) and (3) are not satisfied. {circle
around (2)} means "content maximum value/content minimum value".
Object element is shown in parentheses. "X" in "Bending
Workability" means that formula (b) is not satisfied.
[0101] In the "Evaluation" column of bending workability of the
tables, "O" shows those satisfying B.ltoreq.2.0 in plate materials
having tensile strength TS of 800 MPa or less and those satisfying
the following formula (b) in plate materials having tensile
strength TS exceeding 800 MPa, and ".times." shows those that are
not satisfactory. B.ltoreq.41.2686-39.4583 .times.exp
[-{(TS-615.675)/2358.08}.sup.2] (b)
[0102] FIG. 2 is a graph showing the relationship between tensile
strength and electric conductivity in each example. As shown in
Tables 4 to 7 and FIG. 2, regarding the chemical composition, the
content ratio and the total number of the precipitates and the
inclusions are within the ranges regulated by the present invention
in Inventive Examples 1 to 67 and the tensile strength and the
electric conductivity satisfied the above-mentioned formula (a).
Accordingly, it can be said that the balance between electric
conductivity and tensile strength of these alloys are of a level
equal to or higher than that of the Be-added copper alloy. Thus,
the copper alloy of the present invention is found to be rich in
variations of tensile strength and electric conductivity. In
Inventive Examples 1, 6, 11, 16, 34, 36, 37, 39, 41, 64, 65 and 66,
the addition quantity and/or manufacturing condition were minutely
adjusted with the same component system. It can be said that these
alloys have a relationship between tensile strength and electric
conductivity as shown by ".DELTA." in FIG. 2, and also have the
characteristics of the conventionally known copper alloy. Further,
the bending property was also satisfactory.
[0103] On the other hand, Comparative Examples 1 to 4, 6, 10, 12 to
14, 16 and 17 were inferior in bending workability and electric
conductivity because the content of any one of alloying elements is
out of the range regulated by the present invention. For
Comparative Examples 1 to 3 and 17, the characteristics could not
be evaluated since edge cracking in the second rolling was too
serious to collect the samples. Comparative Examples 5, 9, 11 and
15, which were subjected to solution treatment at 950.degree. C.,
were inferior in tensile strength and bending workability.
EXAMPLE 2
[0104] In order to evaluate the application to the safety tools,
samples were prepared by the following method, and evaluated for
wear resistance (Vickers hardness) and spark resistance.
[0105] Alloys having chemical compositions shown in Table 8 were
melted in a high frequency furnace in the atmosphere, and were cast
by the Durville process. Each bloom was produced by holding a
metallic mold 1 in a state as shown in FIG. 3C (a), pouring a melt
of about 1300.degree. C. into the metallic mold 1 while ensuring a
reducing a.mu.mosphere by charcoal powder, then tilting the mold as
shown in FIG. 3C (b), and solidifying the melt in a state shown in
FIG. 3 (c). The metallic mold 1 is made of cast iron with a
thickness of 50 mm, and has a pipe arrangement with a cooling hole
bored in the inner part so that air cooling can be performed. The
bloom was made to a wedge shape having a bottom section of
30.times.300 mm, an upper section of 50.times.400 mm, and a height
of 700 mm so as to facilitate the pouring of the melt.
[0106] A part up to 300 mm from the lower end of the resulting
bloom was prepared followed by surface-polishing, and then
subjected to cold rolling (30.fwdarw.10 mm) and heat treatment
(375.degree. C..times.16h), whereby a plate 10 mm thick was
obtained. Such a plate was examined for the total number of the
precipitates and the inclusions, tensile strength, electric
conductivity, and bending workability by the above-mentioned method
and, further, examined for wear resistance, thermal conductivity
and spark generation resistance by the method described below. The
results are shown in Table 8.
.ltoreq.Wear Resistance>
[0107] A specimen of 10 mm width.times.10 mm length was prepared
from each specimen, a section vertical to the rolled surface and
parallel to the rolling direction was polish-finished, and the
Vickers hardness at 25.degree. C. and load 9.8N thereof was
measured by the method regulated in JIS Z 2244.
.ltoreq.Thermal Conductivity>
[0108] The thermal conductivity [TC (W/mK)] was determined by the
use of the electric conductivity [IACS(%)] from the formula
described in FIG. 1, i.e., "TC=14.804+3.8172.times.IACS". <Spark
Generation Resistance>
[0109] A spark test according to the method regulated in JIS G 0566
was performed by use of a table grinder having a rotating speed of
12,000 rpm, and the spark generation was visually confirmed.
[0110] The average cooling rate to 450.degree. C. based on the
liquidus induced by the heat conduction calculation with the
temperature measured by inserting a thermocouple to a position of 5
mm under the mold inner wall surface in a position 100 mm from the
bottom, was determined to be 10.degree. C./s. TABLE-US-00008 TABLE
8 Bending Chemical Composition Grain Tensile Workability Wear
Thermal Spark (mass %, Balance: Cu & Impurities) Size Strength
Conductivity B Resistance Conductivity Generation Division Hf Ti Zr
Sn Mg P {circle around (1)} (.mu.m) (MPa) (%) (R/t) Evaluation (Hv)
(W/m K) Resistance Examples 68 -- -- 1.0 0.5 0.01 0.01
.circleincircle. 25 1110 32 2 .largecircle. 342 137 Non of The 69
-- 1.5 -- 0.4 -- 0.05 .circleincircle. 12 1058 29 2 .largecircle.
327 126 Non Present 70 2.0 -- -- 1.2 0.1 -- .circleincircle. 20 998
35 2 .largecircle. 310 148 Non Invention Com- 18 -- 5.4* -- --
0.001 0.1 X 2 1402 1 6 X 426 19 Generated parative Examples 19 --
-- 6.0* 1.5 0.1 -- X 1 1395 1 6 X 424 19 Generated
".circleincircle." in {circle around (1)} means that formula (3)
are satisfied, "X" means that formulas (1), (2) and (3) are not
satisfied respectively. ".largecircle." in "Bending Workability"
means that formula (b) is satisfied. "X" means that formula (b) is
not satisfied.
[0111] As shown in Table 8, no spark was observed with satisfactory
wear resistance and high thermal conductivity in Inventive Examples
68 to 70. On the other hand, sparks were observed with low thermal
conductivity in Comparative Examples 18 and 19, since they did not
satisfy the chemical composition regulated by the present invention
and the relationship shown by formula (1).
Industrial Applicability
[0112] According to the present invention, a copper alloy that has
wide product variations, and is excellent in high-temperature
strength and workability, and also excellent in the performances
required for safety tool materials, or thermal conductivity, wear
resistance and spark generation resistance, and a method for
producing the same can be provided.
Brief Description of the Drawings
[0113] FIG. 1 A graph showing the relationship between the electric
conductivity and thermal conductivity;
[0114] FIG. 2 A graph showing the relationship between the tensile
strength and the electric conductivity of each of examples.
[0115] FIG. 3 A schematic view showing a casting method by the
Durville process.
EXPLANATION OF LETTERS
[0116] 1: metallic mold
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