COPPER ALLOY
DATA SHEET
C18200
Chromium Copper C18200 is a heat treatable
copper alloy offering good electrical conductivity, resistance to softening at
elevated temperatures and good strength and hardness. This combination of properties makes C18200
one of the preferred resistance welding electrode materials for a variety of
applications. Nominally composed of
99.1% copper and 0.9% chromium, this heat treatable alloy can be brought to its
softest condition by annealing it at 1000°C (1850°F) for one-half hour at temperature, then
rapidly quenching it in water. In this
annealed condition, the alloy is ductile and easily formed, and has an
electrical conductivity of about 40% IACS.
After softening in this manner, C18200 may be
hardened back to some degree by cold working.
However, the alloy also may be hardened by simply exposing it to a
controlled temperature range between 425-500°C (800-930°F) for two to four hours. A similar treatment applied to cold worked
material imparts additional hardness and strength. In either case, age hardening treatment
considerably improves the electrical conductivity (increasing it to about 80%
IACS), as well as the mechanical properties which are retained to a great
degree even at elevated temperatures above 200°C (375°F). At
this temperature, C18200 has a tensile strength about twice that compared to
electrolytic tough pitch (ETP) C11000 and Silver Coppers C10400, C10500, and
C10700 at the same temperature.
Hot Working: Alloy
C18200 can be hot worked, but after hot working, it is necessary to solution
anneal the articles by heating at 1000°C (1850°F) and quenching rapidly before applying the
age hardening treatment. For both
solution annealing and age hardening, the furnace atmosphere should be kept
neutral or slightly reducing in order to minimize scale formation.
Cold Working: Cold
workability is excellent. When the
ultimate application requires only machining, rod and bar may be obtained from
the mill in the fully hardened condition.
If, however, cold forming operations are necessary, the stock should be
ordered in the soft, solution annealed condition or in a suitable drawn,
temper, and age hardened condition after the work is completed. We can suggest suitable times and temperatures
for heat treatment for a particular application.
Joining: Welding and
brazing temperatures degrade the properties developed by heat treatment, and
such processes are seldom used for joining this alloy except in the softened
condition.
Applications: Although Chromium Copper C18200 is most commonly
used for resistance welding equipment, it is also used for circuit breaker
parts, current carrying shafts and arms, electron tube grid side rods,
electrical connectors, heat sinks, plastic mold components, and switchgear.
Applicable Specifications: Chromium Copper C18200 Rod is generally
manufactured to the latest revision of RWMA-Bulletin 16, Group A, Class 2 for
resistance electrodes.
Standard Forms Available: Rod, bar, wire and shapes. For other forms, please contact Ansonia
Copper & Brass, Inc.
Ansonia Copper & Brass, Inc. can supply
Chromium Copper C18200 in several different grades, depending on your
particular application. RWMA Class 2
material is suitable for machining. When
material is supplied to meet this requirement, it is fully heat treated so no
additional heat treating is required. If
bending is required, specify Ansonia Copper & Brass
Bending Quality. Rod for
hot forging is also available in the unaged plain extruded condition. Regardless of what properties you are
interested in, Ansonia Copper & Brass' metallurgists can customize this
alloy's heat treating properties to meet your particular needs.
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ADS No. 18200 |
Rev. No. 1 |
Rev. Date 6/23/99 |
C18200 |
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P. O. Box 109 - Ansonia,
Connecticut 06401 |
725 Bank St. - Waterbury,
Connecticut 06708 |
Tel.: 1-800-521-1703 FAX 203-735-3787 |
Tel.: 1-800-243-3204 FAX 203-756-1330 |
PROPERTIES OF C18200
Nominal Composition: 99.1% Copper
0.9% Chromium
Physical Properties:
Melting Point (Liquidus): 1075°C (1967°F)
(Solidus): 1070°C (1958°F)
Density
at 68°F: 0.321
Lbs./In.3
Coefficient of Linear Expansion per °F: 9.8 x 10-6 (77-212°F)
Electrical Conductivity at 68°F: 80% IACS (solution heat treated, cold worked 50% minimum and aged)
Thermal Conductivity Btu/ft.2/ft./hr./°F: 187 (solution heat treated, cold worked 50% minimum and aged)
Modulus of Elasticity - Tension: 17,000 ksi
Modulus of Rigidity: 7,200 ksi
Fabrication
Properties:
Hot Working Temperature: 800-925°C (1500-1700°F)
Approximate Relative Machinability: 20 (free cutting brass arbitrarily rated at 100)
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Mechanical Properties: |
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Rod Size |
Temper
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Tensile Strength (psi) |
Yield Strength (0.5% EUL) (psi) |
% Elongation (in 2") |
Rockwell Hardness |
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0.156"
Dia. |
TD10 |
SA-CW
91% |
74,000 |
73,000 |
5 |
-- |
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0.156"
Dia. |
TH10 |
SA-CW
90% - HT |
86,000 |
77,000 |
14 |
-- |
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0.500"
Dia. |
TB00 |
SA |
45,000 |
14,000 |
40 |
-- |
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0.500"
Dia. |
TD04 |
SA-CW
61% |
57,000 |
56,000 |
11 |
HRB 65 |
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0.500"
Dia. |
TH04 |
SA-CW
61% |
77,000 |
65,000 |
16 |
HRB 82 |
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0.500"
Dia. |
TF00 |
SA-HT |
70,000 |
55,000 |
21 |
HRB 70 |
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1.0"
Dia. |
TF00 |
SA-HT |
72,000 |
65,000 |
18 |
HRB 80 |
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2.0"
Dia. |
TF00 |
SA-HT |
70,000 |
65,000 |
18 |
HRB 75 |
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3.0"
Dia. |
TF00 |
SA-HT |
65,000 |
55,000 |
18 |
HRB 70 |
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4.0"
Dia. |
TF00 |
SA-HT |
55,000 |
43,000 |
25 |
HRB 68 |
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SA
= Solution Anneal, HT = Heat Treat (Age), CW = Cold Work |
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Fatigue Strength (psi) (300 million cycles) |
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Hard Drawn
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72,800 |
25,800 |
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Hard Drawn and Age Hardened
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76,800 |
28,000 |
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ADS No. 18200 |
Rev. No. 1 |
Rev. Date 6/23/99 |
C18200 |
The
statements and data provided on this data sheet are to be considered only as a
general guide. Commercial variations in
material properties are expected, so values listed here are not intended to be
used for specifications. Please consult
the appropriate industry specifications where applicable. Ansonia Copper & Brass, Inc. also cannot
assume responsibility for performance of these products in service because we
do not control or supervise subsequent use of our products.