Processing of copper alloys

This invention is directed to the treatment of copper beryllium alloys, and to articles and parts made therefrom, containing special small amounts of beryllium and nickel, e.g., about 0.05% to about 0.5% beryllium and about 0.05% to about 1% nickel where cobalt may be substituted for up to about one-half of said nickel content at a substitution ratio of about 1 part by weight cobalt for about 2 parts by weight nickel, which imparts to these alloys a superior combination of stress relaxation resistance, formability, ductility, conductivity and strength by the process of solution annealing, cold working at least about 50% or at least about 70% or 90% or more and age hardening.

The present invention is directed to a metallurgical process for wrought 
copper alloys, specifically alloys containing small interrelated amounts 
of beryllium and nickel, or nickel plus cobalt in combination, to produce 
useful articles having an improved combination of stress relaxation 
resistance, formability, conductivity and strength. 
BACKGROUND OF THE INVENTION AND THE PRIOR ART 
Copper beryllium alloys have been used commercially for approximately fifty 
years in applications requiring high strength, formability, stress 
relaxation resistance and conductivity. Historical development of copper 
beryllium alloys and the processes to manufacture them has generally 
proceeded in the direction of providing premium performance, i.e., the 
highest strengths, best ductilities and other highly desirable attributes, 
by taking advantage of the precipitation hardening characteristics of 
these alloys. Thus, U.S. Pat. Nos. 1,893,984, 1,957,214, 1,959,154, 
1,974,839, 2,131,475, 2,166,794, 2,167,684, 2,172,639 and 2,289,593 
disclose various wrought alloys containing varying amounts of beryllium 
and other elements. Commercial copper beryllium alloys include those 
wrought alloys bearing Copper Development Association designations C17500, 
C17510, C17000, C17200 and C17300. 
In the fifty or so years since the above-discussed patents were granted, 
whole new industries have appeared and new sets of requirements have been 
imposed on alloy producers. Thus, the requirements of the electronics and 
computer industries were unknown in the 1930's. Even the trends toward 
miniaturization in electronics and computers have arisen and proceeded at 
an accelerating pace only in the past few years. In the provision of 
spring-type connectors and contacts, the complexity of the devices needed, 
and the requirements for heat dissipation, as well as for survival of 
parts at elevated temperatures without failure due to stress relaxation, 
have proceeded apace. In addition, purchasers have become increasingly 
price-conscious and connector alloys such as phosphor bronzes C51000 and 
C52100 have been employed due to cost even though the inferior performance 
of such alloys, such as in poorer conductivity, poorer formability and 
lower stress relaxation resistance as compared to copper beryllium alloys, 
was known. Moreover, the formability requirements imposed by the 
production of complex parts from strip or wire using progressive dies and 
other metal forming technologies, and the need for greater resistance to 
stress relaxation demanded by today's high reliability electrical and 
electronic connector, switch and relay applications, have elevated the 
difficulties imposed upon alloy suppliers as compared to the simpler days 
of U.S. Pat. Nos. 1,893,984 and 2,289,593 wherein the compositions and 
processing of copper beryllium alloys were intended only to obtain maximum 
strength-conductivity relationships, and no reference was made to 
considerations of formability or stress relaxation behavior. 
Processes in the prior art to produce wrought forms (i.e., strip, plate, 
wire, rod, bar, tube, etc) of copper beryllium alloys have generally 
focused on the premium performance alloys with beryllium and major third 
element contents reminiscent of the composition of commercial alloys 
C17500, C17510 and C17200. These processes have generally included the 
steps of preparing the molten alloy, casting an ingot, converting the 
ingot to a wrought form by hot and/or cold working with optional 
intermediate anneals to maintain workability of the alloy, solution 
annealing the wrought form by heating to a temperature sufficient to 
effect recrystallization of the alloy and solid solution of the beryllium 
in the copper matrix and then rapidly quenching the alloy to retain the 
beryllium in supersaturated solid solution, optionally cold working the 
solution annealed wrought form a predetermined amount to enhance the 
subsequent age hardened strength, then age hardening the optionally cold 
worked wrought form at temperatures less than the solution annealing 
temperature to achieve desirable combinations of strength and ductility. 
This art is disclosed in U.S. Pat. Nos. 1,893,984, 1,959,154, 1,974,839, 
1,975,113, 2,027,750, 2,527,983, 3,196,006, 3,138,493, 3,240,635, 
4,179,314 and 4,425,168 which also teach that optimum solution annealing 
and aging temperature ranges are dependent upon alloy composition, and 
that age hardening may be performed either before, during or after the act 
of fabricating the solution annealed and optionally cold worked wrought 
form into an article of manufacture (e.g., an electrically conductive 
spring, pressure welding electrode, or similar device) by well-known metal 
forming technologies. 
Copper-base alloys of the prior art which are not age hardenable (such as 
C51000 and C52100 phosphor bronzes) and which derive their strength solely 
from work hardening are frequently cold worked substantially beyond 50% 
reduction in area in order to achieve commercially significant strength 
levels. In the case of copper beryllium alloys of the prior art, final 
cold work applied between solution annealing and age hardening, other than 
that associated with any parts-fabrication metal forming operations, 
generally is confined to levels less than about 50% reduction. Thus, U.S. 
Pat. Nos. 3,138,493, 3,196,006, 4,179,314 and 4,425,168 describe processes 
involving a minimum of 3% to a maximum of 42% cold reduction prior to age 
hardening. One explanation of this restriction on cold work in the 
commercial copper beryllium alloys of the prior art is given in the 1982 
publication "Wrought Beryllium Copper" by Brush Wellman Incorporated, 
which shows that as-rolled ductility (and hence formability--the minimum 
bend radius for no cracking when bent 90.degree. or 180.degree. in a 
forming operation) degrades to commercially unacceptable levels as 
pre-aging cold work increases beyond about 40% reduction, and that 
post-cold working age hardened strength exhibits a relative maximum at 
about 30% to 40% cold reduction, but decreases with larger amounts of cold 
work when the alloys are aged at commercially recommended times and 
temperatures. 
Copending application Ser. No. 550,631 by Amitava Guha, assigned to Brush 
Wellman Inc., describes an improved process for commercial 
copper-beryllium-nickel alloy C17510 involving cold work of up to about 
90% intermediate to a special high temperature solution annealing 
treatment to form a nickel-rich precipitate and a low temperature age 
hardening step, the whole intended to develop strength and electrical 
conductivity combinations previously unobtainable in C17500 and C17510, 
with little or no sacrifice in formability and resistance to stress 
relaxation. U.S. Pat. No. 2,289,593 also discloses copper-beryllium-nickel 
alloys cold worked in one instance as much as 80% prior to aging, but this 
is in reference to an alloy containing at least 1.47% Ni, and only 
electrical conductivity is reported. 
The property of stress relaxation is an important design parameter which 
can give the designer assurance that a particular contact or connector or 
like device will maintain the required contact pressure to assure 
long-life performance of an assembly including the device. Stress 
relaxation is defined as the decrease of stress at constant strain with 
time for a given temperature. From a knowledge of the stress relaxation 
behavior of a material, a designer can determine how much the room 
temperature spring force must be increased to assure a particular minimum 
force at operating temperature to maintain electrical contact between 
mating parts for an extended time period. 
The stronger beryllium-containing age hardenable alloys such as C17200, 
which contains about 2% beryllium, are known to have high resistance to 
stress relaxation. On the other hand, the considerably cheaper phosphor 
bronzes, such as C51000 and C52100, which are non-agehardenable and have 
to be severely cold worked to achieve high strength, are poor with respect 
to resistance to stress relaxation. 
As used herein, stress relaxation resistance is determined by the test 
described in the paper entitled "Stress Relaxation of Beryllium Copper 
Strip in Bending" by Harkness and Lorenz presented at the 30th Annual 
Relay Conference, Stillwater, Okla., Apr. 27-28, 1982. In accordance with 
this test, flat spring specimens having a tapered gage length are stressed 
in a fixture to a constant initial stress level and are exposed with the 
fixture in the stressed condition to an elevated temperature such as 
300.degree. F. (150.degree. C.) for an extended time period. Periodically, 
a specimen is removed and measured to determine the amount of permanent 
set the material has undergone, from which the percent of remaining stress 
value can be calculated. 
Formability is determined by bending a flat strip specimen about a punch 
having a nose of variable known radius with failure being taken as the 
point at which cracking occurs in the outer fibers of the bend. A rating 
is given for the test from the quantity R/t wherein "R" is the radius of 
the smallest punch nose which causes no cracking and "t" is the thickness 
of the strip. The rating can be used by designers to determine whether a 
particular material can be formed to the geometry desired in a particular 
part. 
The present invention provides a process to produce age hardenable copper 
beryllium alloys containing small amounts of nickel, where cobalt may be 
substituted for a portion of said nickel content, having a 
stress-relaxation resistance approaching that of the strongest copper 
beryllium alloys of commerce together with high formability and ductility, 
high conductivity and useful strength. Our copending application Ser. No. 
623,463, "Processing of Copper Alloys", relates to a processing technique 
for copper beryllium alloys containing small amounts of cobalt.

SUMMARY OF THE INVENTION 
The invention is directed to the treatment of copper beryllium alloys 
containing about 0.05% to about 0.5% beryllium and about 0.05% to about 1% 
nickel where cobalt may be substituted for up to about one-half of said 
nickel content at a substitution ratio of about 1 part by weight cobalt 
for 2 parts by weight nickel. The treatment consists of solution annealing 
said alloy in the temperature range of about 1600.degree. F. (870.degree. 
C.) to about 1850.degree. F. (1000.degree. C.), preferably about 
1600.degree. F. (870.degree. C.) to about 1700.degree. F. (930.degree. 
C.), cold working said alloy to reduce the section thickness thereof by at 
least about 50%, preferably at least about 70% to about 95%, and aging 
said cold worked alloy in the temperature range of about 600.degree. F. to 
about 1000.degree. F. (315.degree. C. to about 540.degree. C.) for times 
of less than 1 to about 8 hrs. to provide in said aged alloy a high 
combination of stress relaxation resistance, formability, ductility, 
conductivity and strength. 
DETAILED DESCRIPTION OF THE INVENTION 
The invention is grounded in the discovery that beryllium copper alloys 
having small, definite contents of beryllium and of nickel, where a 
portion of said nickel content may be replaced with a definite amount of 
cobalt, are capable of providing highly useful combinations of stress 
relaxation resistance, formability and ductility, conductivity and 
strength when processed by solution annealing, heavy cold working and 
aging. Indeed, we have discovered that as these alloys are age hardened 
after cold working in excess of about 50% reduction in area, both 
strength, as measured by the 0.2% offset yield strength, and ductility, as 
measured by tensile elongation, improve considerably with increasing cold 
work up to about 95% reduction or more compared to aged material with cold 
work of less than 50%. The alloys contain about 0.05% to about 0.5% 
beryllium and about 0.05% to about 1% nickel where cobalt may be 
substituted for up to about one-half of said nickel content at a 
substitution ratio of about 1 parts by weight cobalt for 2 parts by weight 
cobalt, and the processing which is applied after any hot or cold working 
required to convert the original cast ingot to an intermediate shape of 
appropriate dimension, comprises a solution treatment in the temperature 
range of about 1600.degree. F. (870.degree. C.) to about 1850.degree. F. 
(1000.degree. C.), preferably about 1600.degree. F. (870.degree. C.) to 
about 1700.degree. F. (930.degree. C.), followed by cold working, as by 
rolling, to reduce the section of the intermediate shape by at least about 
50% up to about 70% to about 95% or more followed by aging the resulting 
cold worked shape in the temperature range of about 600.degree. F. to 
about 1000.degree. F. (315.degree. C. to about 540.degree. C.) for less 
than about one hour to about 8 hours. The treatment differs from the 
commercial processing of copper beryllium alloys in the extent of cold 
work applied to the alloys prior to aging and differs from that of 
copending application Ser. No. 550,631 by Amitava Guha, assigned to Brush 
Wellman Inc., in the annealing temperatures employed and in the lack of 
formation of a nickel-rich precipitate at such annealing temperatures. 
The treatment provides in the alloys, which are low in alloy constituents 
as compared to commercially produced wrought copper beryllium alloys, a 
useful and quite unexpected combination of properties. In particular, the 
alloys display a superior combination of stress relaxation resistance, 
formability and ductility and conductivity as compared to existing bronze 
and brass alloys, e.g., the phosphor bronzes, having similar strength. 
The alloys may be cast to ingot using conventional static, semi-continuous 
or continuous casting techniques. The ingots may readily be worked, as by 
hot or cold rolling, without difficulty. Intermediate anneals at 
temperatures between about 1000.degree. F. (540.degree. C.) and 
1750.degree. F. (955.degree. C.) may be employed. Once the ingot is 
reduced to the desired intermediate gage, from which cold reduction to 
desired final gage with a predetermined amount of cold work may be 
imposed, a solution anneal is employed. Solution annealing is accomplished 
at temperatures of about 1600.degree. F. (870.degree. C.) to about 
700.degree. F. (930.degree. C.) to 1850.degree. F. (1000.degree. C.). 
Temperatures lower than this range will not effect complete 
recrystallization in some alloys. Temperatures at the low end of this 
range will give finer grain size and better formability but with poorer 
strength. There may be undesirable grain growth with some alloys within 
the cited range resulting from use of a 1750.degree. F. (950.degree. C.) 
or greater solution treatment. The solution-treated material is then cold 
worked to substantially finish gage, as by rolling, drawing or other metal 
deformation processes, to reduce the cross section thereof by at least 
about 50%, preferably at least about 70% to about 90% or more. The cold 
worked material is then aged at a temperature within the range of about 
600.degree. F. (315.degree. C.) to about 1000.degree. F. (540.degree. C.), 
for less than about 1 to about 8 hours. 
Aging acts as both a precipitation hardening and a stress-relieving heat 
treatment. The effect of aging is to increase strength while also greatly 
increasing ductility and resistance to stress relaxation of the alloy. 
Formability is also markedly increased. For aging temperatures below about 
750.degree. F. (400.degree. C.) aging times of at least about 1 to about 7 
hours are employed, while higher aging temperatures require about one hour 
or less aging time. Lower beryllium contents also require longer aging 
times than higher beryllium contents to achieve desirable property levels. 
EXAMPLES WILL NOW BE GIVEN 
A series of alloys having the compositions set forth in Table I was 
produced in ingot form. The ingots were converted to strip of intermediate 
gage by hot and cold rolling with optional intermediate anneals. The 
worked strip was then solution annealed at the temperatures shown in Table 
I for times of about 5 minutes or less at temperature, followed by a rapid 
quench to room temperature. The solution annealed strip was then cold 
rolled to 72% reduction in thickness and age hardened at the times and 
temperatures indicated. Tensile properties, hardness and conductivity were 
determined and are reported in the Table. For comparison, strip samples of 
Heats 4 and 5 processed as above through the 72% cold working operation 
but not age hardened exhibited as-rolled tensile properties of 65.5-67.3 
ksi (450-460 MPa) ultimate tensile strength, 63.8-66.1 ksi (440-455 MPa) 
0.2% yield strength, 5.2-5.6% elongation, a hardness of R.sub.B 78 and 
electrical conductivity of 43.9-44.1% IACS. 
Table II contains the results obtained from strip made from certain alloys 
in Table I and an additional composition within the invention, processed 
as those of Table I except cold rolled 82% prior to age hardening as 
indicated. 
Table III shows results for certain of the alloys from Tables I and II cold 
rolled 90% to 93% prior to aging as indicated and includes results of 
90.degree. bend formability tests and stress relaxation tests at 
300.degree. F. (150.degree. C.) and an initial stress of 75% of the 0.2% 
offset yield strength. In this instance, sample strip of Heat 3 processed 
as shown through the 90% cold rolling operation but not age hardened 
exhibited as-rolled tensile properties of 79.0 ksi (545 MPa) ultimate 
tensile strength, 75.9 ksi (525 MPa) 0.2% yield strength, 2.5% elongation, 
a hardness of R.sub.B 82 and an electrical conductivity of 42.2% IACS. 
As-rolled longitudinal 90.degree. bend formability (minimum R/t for no 
cracking) was zero. 
In another example, an alloy containing 0.29% Be, 0.26% Co, balance copper, 
solution annealed at 1650.degree. F. (900.degree. C.), cold rolled 90% and 
aged 5 hours at 750.degree. F. (400.degree. C.) attained properties of 107 
ksi (757 MPa) ultimate tensile strength, 98 ksi (676 MPa) 0.2% yield 
strength, 9% elongation, R.sub.B 98 hardness, 55% IACS electrical 
conductivity, miminum longitudinal 90.degree. bend formability (R/t) of 
1.5, and a "stress-remaining" value of 88% after 1000 hrs. at 300.degree. 
F. (150.degree. C.) and an initial stress of 75% of the 0.2% offset yield 
strength. 
In yet another example, an alloy containing 0.30% beryllium, 0.49% cobalt, 
balance copper, solution annealed at 1700.degree. F. (930.degree. C.), 
cold rolled 90%, and aged 5 hours at 750.degree. F. (400.degree. C.) 
exhibited properties of 126 ksi (869 MPa) ultimate tensile strength, 120 
ksi (827 MPa) 0.2% offset yield strength, 7% elongation, R.sub.B 101 
hardness, 55% IACS electrical conductivity, and a minimum longitudinal 
90.degree. bend formability (R/t) of 0.6. 
The role of the final aging treatment in improving the properties of these 
solution annealed and heavily cold rolled alloys is further demonstrated 
in FIG. 1 where an 11% improvement in strength and a 6-fold increase in 
ductility are observed in 90% or more cold rolled 0.26% beryllium, 0.47% 
nickel, balance copper strip upon aging at 700.degree. F. (370.degree. 
C.). Likewise, a 23% strength improvement and 5-fold ductility increase 
are observed in 90% or more cold rolled 0.27% beryllium, 0.71% nickel, 
balance copper strip upon aging at this same temperature. 
As shown in FIG. 4, stress relaxation resistance of the annealed, heavily 
cold worked and aged alloys of the invention is similar to that of 
commercial C17500 and C17510 strip, approaches that of the higher strength 
precipitation hardened alloys of the prior art, e.g., C17200, and shows 
considerable improvement over the non-precipitation hardenable, cold 
worked alloys of the prior art, e.g., C51000 and C52100 having comparable 
strength. 
Inspection of these examples reveals that at least about 0.15% to about 
0.2% beryllium and about 0.2% nickel, balance copper are necessary to 
achieve desirable combinations of electrical conductivity exceeding about 
40% IACS and strength exceeding about 70 ksi (480 MPa) 0.2% offset yield 
strength when processed per the invention, and that no significant 
improvement in strength beyond about 120 ksi (825 MPa), but a significant 
loss in electrical conductivity is obtained for beryllium content beyond 
about 0.5% and nickel content beyond about 0.9% to about 1%, balance 
copper, when processed per the invention. On the other hand, very high 
electrical conductivity exceeding about 60% IACS, with modest yield 
strengths of at least about 50 ksi (345 MPa) may be obtained from alloys 
with as little as 0.15% beryllium and 0.1% nickel, balance copper when 
processed according to the invention. It is further noted upon inspection 
of these examples that cobalt may be substituted for any portion of the 
nickel content of the alloys of this invention at an approximate 
substitution ratio of about 1 part by weight cobalt for about 2 parts by 
weight nickel and achieve reasonably comparable mechanical and physical 
properties at a given beryllium content. 
Wrought forms processed in accordance with the invention are useful for 
current-carrying springs, mechanical springs, diaphragms, switch blades, 
contacts, connectors, terminals, fuse clips, bellows, die casting plunger 
tips, sleeve bearings, tooling to mold plastics, oil/coal drilling 
equipment components, resistance welding electrodes and components, lead 
frames, etc. 
In addition to useful articles fabricated from alloy strip, plate, rod, bar 
and tube processed to finished form by the annealing, cold working and age 
hardening processes of the invention, we also recognize other approaches 
to the fabrication of such articles which lie within the scope of the 
invention. Thus clad, roll bonded, or inlaid strip or wire; wherein a 
layer of a first wrought metallic substance, e.g., a copper-base alloy, a 
nickel-base alloy, an iron-base alloy, a chromium-base alloy, a 
cobalt-base alloy, an aluminum-base alloy, a silver-base alloy, a 
gold-base alloy, a platinum-base alloy or a palladium-base alloy, or any 
combination of two or more of the above is metallurgically joined to a 
substrate of a second metallic substance consisting of a copper beryllium 
alloy within the range of the invention; may be fabricated by placing the 
layer or layers of said first metallic substance or substances in contact 
with the suitably cleaned surface of said solution annealed second 
metallic substance, cold rolling (or, in the case of wire, drawing) the 
superimposed metallic substances to a heavy reduction within the range of 
the invention, e.g., 50% to 70% or even 90% or more, to effect a cold 
weld, then age hardening the resultant multi-layered strip or wire within 
the range of the invention, e.g., 600.degree. F. to 1000.degree. F. 
(315.degree. C. to 540.degree. C.) for less than one hour to about 8 
hours, to produce a desirable combination of strength, ductility, 
formability, conductivity and stress relaxation resistance in the 
substrate copper beryllium material. 
Additionally, useful articles may be fabricated from alloys within the 
invention wherein the substantially final form of the article is produced 
by heavy cold working, e.g., cold forging, cold swaging, cold coining, or 
cold heading, the solution annealed and optionally partially cold rolled 
or drawn wrought alloy strip, plate, rod, bar, wire or forging blank to 
final dimensions to effect a total degree of cold work in the alloy within 
the range of the invention, e.g., 50% to about 70% or 90% or more, then 
age hardening the cold formed final article within the range of the 
invention, e.g., 600.degree. F. to 1000.degree. F. (315.degree. C. to 
540.degree. C.) for less than one to about 8 hours, to impart to the final 
articles desirable property combinations of the alloys within the 
invention. 
Although the present invention has been described in conjunction with 
preferred embodiments, it is to be understood that modifications and 
variations, may be resorted to without departing from the spirit and scope 
of the invention, as those skilled in the art will readily understand. 
Such modifications and variations are considered to be within the purview 
and scope of the invention and appended claims. 
TABLE I 
__________________________________________________________________________ 
Elonga- Minimum 
Ultimate 
0.2% tion Electrical 
Longi- 
Composition Tensile 
Yield in 2 in. 
Hard- 
Conduc- 
tudinal 
Heat 
(Bal. Cu) Anneal Age Strength 
Strength 
(50 mm) 
ness 
tivity 
90.degree. 
Bend 
No. 
% Be 
% Ni 
% Co 
F C F C Hr. 
ksi 
MPa 
ksi 
MPa 
% R.sub.B 
% IACS 
R/t 
__________________________________________________________________________ 
1 0.19 
0.96 
-- 1700 
930 700 
370 
7 112.4 
775 
101.7 
700 
9.0 90 55.1 0.8 
2 0.15 
1.35 
-- 1850 
1010 
700 
370 
2 113.5 
785 
104.8 
725 
12.5 101 30.5 -- 
3 0.29 
0.49 
-- 1700 
930 700 
370 
7 105.9 
730 
93.3 
640 
11.2 87 53.2 0.9 
4 0.27 
0.54 
-- 1700 
930 700 
370 
7 107.6 
740 
95.6 
660 
13.4 96 56.3 -- 
5 0.26 
0.54 
-- 1750 
955 700 
370 
7 104.1 
715 
90.4 
620 
16.3 97 55.8 -- 
6 0.26 
0.71 
-- 1700 
930 700 
370 
7 117.0 
805 
103.5 
715 
13.6 98 55.8 -- 
7 0.50 
0.10 
-- 1650 
900 700 
370 
3 79.8 
550 
66.6 
460 
15.4 85 42.8 -- 
8 0.50 
0.13 
-- 1700 
930 700 
370 
7 84.6 
585 
71.1 
490 
11.6 75 40.2 0.6 
9 0.51 
0.22 
-- 1700 
930 750 
400 
3 -- -- -- -- -- 92 41.0 -- 
10 0.49 
0.96 
-- 1700 
930 700 
370 
7 131.0 
900 
118.9 
820 
12.2 95 42.4 0.8 
10 0.49 
0.96 
-- 1750 
955 750 
400 
7 129.0 
890 
115.5 
795 
14.6 103 45.1 -- 
11 0.71 
0.14 
-- 1700 
930 750 
400 
3 -- -- -- -- -- 89 36.0 -- 
12 0.70 
0.23 
-- 1700 
930 700 
370 
3 101.8 
700 
86.8 
595 
12.6 90 35.7 0.4 
13 0.30 
0.11 
0.10 
1700 
930 750 
400 
3 -- -- -- -- -- 90 49.0 -- 
14 0.29 
0.30 
0.16 
1700 
930 700 
370 
7 112.3 
770 
102.2 
705 
10.2 87 52.0 0.8 
15 0.39 
0.11 
0.10 
1650 
900 750 
400 
3 -- -- -- -- -- 94 44.8 -- 
16 0.52 
0.11 
0.08 
1700 
930 750 
400 
3 -- -- -- -- -- 97 38.5 -- 
__________________________________________________________________________ 
TABLE II 
__________________________________________________________________________ 
Elonga- Minimum 
Ultimate 
0.2% tion Electrical 
Longi- 
Composition Tensile 
Yield in 2 in. 
Hard- 
Conduc- 
tudinal 
Heat 
(Bal. Cu) Anneal 
Age Strength 
Strength 
(50 mm) 
ness 
tivity 
90.degree. 
Bend 
No. 
% Be 
% Ni 
% Co 
F C F C Hr. 
ksi 
MPa 
ksi MPa 
% R.sub.B 
% IACS 
R/t 
__________________________________________________________________________ 
17 0.19 
0.10 
-- 1700 
930 
700 
370 
7 70.0 
480 
63.3 
435 
6.7 72 61.1 0.6 
3 0.29 
0.49 
-- 1700 
930 
700 
370 
7 107.4 
740 
96.4 
665 
9.9 87 54.6 0.4 
7 0.50 
0.10 
-- 1700 
930 
700 
370 
7 80.7 
555 
66.9 
460 
13.4 83 43.8 0.6 
10 0.49 
0.96 
-- 1700 
930 
700 
370 
7 132.1 
910 
121.4 
835 
8.5 99 44.1 0.6 
__________________________________________________________________________ 
TABLE III 
__________________________________________________________________________ 
Ultimate 
0.2% 
Composition Tensile 
Yield 
Heat 
(Bal. Cu) Anneal 
Age Strength 
Strength 
No. 
% Be 
% Ni 
% Co 
F C F C Hr. 
ksi 
MPa 
ksi MPa 
__________________________________________________________________________ 
17 0.19 
0.10 
-- 1750 
950 
800 
425 
3 59.7 
410 
46.8 
320 
1 0.19 
0.96 
-- 1650 
900 
700 
370 
7 107.0 
735 
99.4 
685 
3 0.27 
0.54 
-- 1700 
930 
700 
370 
7 111.2 
765 
94.2 
650 
5 0.29 
0.49 
-- 1650 
900 
750 
400 
5 -- -- 93.3 
645 
6 0.26 
0.71 
-- 1700 
930 
700 
370 
7 117.5 
810 
107.1 
740 
10 0.49 
0.96 
-- 1650 
900 
800 
425 
5 89.4 
615 
77.4 
530 
14 0.29 
0.30 
0.16 
1650 
900 
700 
370 
7 115.1 
790 
106.3 
730 
14 0.29 
0.30 
0.16 
1650 
900 
750 
400 
5 -- -- 104.2 
715 
__________________________________________________________________________ 
Elongation Minimum 
% Remaining 
in 2 in. Electrical 
Longitudinal 
Stress 
Heat 
(50 mm) 
Hardness 
Conductivity 
90.degree. Bend 
300 F. (150 C.) 
No. 
% R.sub.B 
% IACS R/t 500 hr. 
__________________________________________________________________________ 
17 15.5 29 65.8 0 -- 
1 9.6 81 56.8 1.0 -- 
3 13.1 96 55.1 0 -- 
5 -- -- -- -- 88.8 
6 10.5 97 56.0 0.4 -- 
10 16.3 69 50.6 0.5 -- 
14 10.8 94 53.7 0.2 -- 
14 -- -- -- -- 87.0 
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