tensile testing of c17410 sheet before and after bakeout · asm specialty handbook copper and...
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Tensile testing of C17410 sheet before and after bakeout
Jorge Guardia-Valenzuela (EN-MME-EDS)
HiColDEM meeting 07-Nov-2018
Description of the material
Copper-beryllium
Cu-Be C17410 sheet from CERN store.
Thickness 0.33 mm
2
Specimen preparation
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4 sets of samples:
• AR-RD
• AR-TD
• B-RD
• B-TD
RD - Rolling direction
TD - Transversal direction
AR - As received
B - Baked (standard bake-out 250˚C 48 h.)
Specimens “cut” by chemical etching at CERN
(masking + acid immersion).
Contact Découpe chimique: Bertrand Mehl/Benilde
Martins B.107
Holes were drilled for hanging them in the furnace
(small vacuum furnace at B.112).
(Fritz Motschmann)
Tensile specimen (type 1, Table B.1, annex B of ISO 6892-1)
Transversal
Description of the test
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Tensile tests were carried out at room temperature with a UTS®
electromechanical testing machine equipped with a 200 kN load cell and a
MFA25 contact extensometer according to the ISO 6892-1 requirements.
Main parameters for the test are the following:
Lc: 66 mm
L0: 50 mm
Preload at 10 MPa at 1 MPa.s-1
Method A (strain rate control): 0.10 mm.s-1 (εLc 0.0015 s-1)
Tensile tests and reports done by M.Crouvizier EN-MME-MM
Final report:
https://edms.cern.ch/document/1806321/1
As-received specimens: EDMS 1753333
Results
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Specimen Rp0.2 (MPa) Rm (MPa) A (%) Young modulus (GPa)
AR-RD 634.9 ± 10.2 743.1 ± 8.3 15.6 ± 0.4 126.7 ± 2.8
AR-TD 566.1 ± 10.2 664.8 ± 2.5 21.1 ± 1.1 126.4 ± 7.8
B-RD 611.4 ± 4.2 722.0 ± 2.9 15.9 ± 0.4 129.6 ± 7.6
B-TD 582.6 ± 8.0 672.3 ± 2.6 21.8 ± 1.1 125.6 ± 8.0
Tensile tests results (average ± std deviation).
Rm, Rp0.2 and Elongation are in accordance with given values for this product (CERN stores material
datasheet). Measured Young modulus are a little bit lower than values given in literature [1] (138 GPa).
Baking seems to homogenize tensile properties by decreasing a little yield and tensile strength in rolling
direction and increasing them a little bit in transverse direction. For a same sampling direction, elongation
remain unchanged after baking.
Reference:
[1]. ASM specialty handbook copper and copper alloys, page 473. J.R. Davis 2001.
Effect of bake-outs in the mechanical
performance of CuBe pieces. Comparison between C17200 and C17510/C17410
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Study done in August 2014 (J.Guardia)
Bake-out process
Schematic of the bake-out cycle of the collimators, VACUUM ACCEPTANCE TESTS FOR LHC COLLIMATORS
The collimator’s body is baked during 48 hours at 250°C. In the collimator life, it
is supposed to have 80 cycles of bake-out, which is 3840h ≈ 4000h
Comparison of Stress Relaxation
100
9384
70
55
33
100
97
85
62
20
0
10
20
30
40
50
60
70
80
90
100
50 100 150 200 250 300 350
Rem
ain
ing
stre
ss (
%)
Temperature (⁰C)
Remaining stress after 4000h * 250⁰C value for C17200 (alloy 25) is extrapolated
C17510 (3) andC17410 (174)
C17200 (25)
Alloy C17510 (3) is better in terms of retaining elasticity at high temperatures than
alloy C17200 (25), because at the same temperature, C17200 releases more stress
(or it retains less elasticity) than C17510.
At low temperatures the difference between both alloys is negligible, but C17200 has
a better behaviour.
Reference: Guide for Copper-Beryllium (FR),
BRUSHWELLMAN Engineered Materials
EXAMPLE
1000h, 300°C 42%
Comparison of Ultimate Tensile Strength
0
200
400
600
800
1000
1200
1400
50 150 250 350 450 550
UTS
(M
Pa)
Temperature (⁰C)
Ultimate Tensile Strength (MPa) [1]
C17510(alloy 3)
C17200(alloy 25)
0
10
20
30
40
50
60
70
80
90
100
100 150 200 250 300 350 400 450 500 550
Re
lati
ve U
TS (
%)
Temperature (⁰C)
Relative UTS loss [1]
C17510 (alloy 3)
C17200 (alloy 25)
Despite the lower Ultimate tensile strength at room
temperature in the alloy C17510, his behaviour at high
temperatures is better because its UTS is maintained
up to higher temperature.
In C17200 the UTS starts
to decrease sharply at
250⁰C, on the other hand
in C17510 falls at a
temperature about 400⁰C.
References: [1] SmithMetal Copper Datasheets
[2] S. Calatroni, LRFF Working Group (3rd Meeting)
Yield strength 0.2% offset, MPa
C17510 (alloy 3) HT [1] 650-870
C17200 (alloy 25) ½ H (TD02) [2] 510-650
C17200 (alloy 25) ½ HT (TH02) [2] 1100-1340
AR-RD
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As-received specimens: EDMS 1753333
AR-TD
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AR-RD
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AR-TD
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