EN Division-Materials and Metrology CERN/EN/MME-MM/EDMS1261295

Chemical analysis of the pump head bearing used in CO2 cooling plant designed for the ATLAS IBL and KEK

BELLE2 (japan) cooling system.

1

Domaine / Field: PH-DT Cooling project

Date: 10.1.20123

N° EDMS / EDMS Nr.:1261295

Requérant / Customer: J. Daguin (PH-DT)

Liste de distribution / Distribution list: J. Daguin

EN Division-Materials and Metrology CERN/EN/MME-MM/EDMS1261295 2

Données expérimentales / Experimental data:

Samples : 1 pump head with 2 bearings

Parameters:The client requested the analysis of the bearing of the pump head and comparison with the results of EDMS1258256 where the powder from the filter and filter itself were analysed.

SEM : Sigma ZEISS, SmartSEM software (Inlens detector)X-MAX 50 mm2 SDD detector – Oxford instruments

Redaction / Written by: B. Bartova /EN/MME-MM

Approuvé par / Accepted by: G. ARNAU IZQUIERDO/EN/MME-MM

Expériences / Testing by: B. Bartova /EN/MME-MM

Superviseur / Supervisor: G. ARNAU IZQUIERDO/EN/MME-MM

Bearing 1

Bearing 2

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Chemical analysis of the Bearing 1 by EDS using the beam@20 kV

Element Weight% Atomic% C K 78.26 88.74O K 10.80 9.19Al K 0.32 0.16Si K 1.08 0.52S K 0.72 0.31Ni K 0.74 0.17Sb L 8.08 0.90 Totals 100.00

Element Weight% Atomic% C K 79.66 89.85O K 9.64 8.16Al K 0.33 0.17Si K 1.11 0.53S K 0.59 0.25Ni K 0.59 0.14Sb L 8.08 0.90 Totals 100.00

Element Weight% Atomic% C K 78.24 89.42O K 9.82 8.43Al K 0.33 0.17Si K 0.98 0.48S K 0.67 0.29Ni K 0.75 0.18Sn L 1.17 0.14Sb L 8.03 0.91 Totals 100.00

EN Division-Materials and Metrology CERN/EN/MME-MM/EDMS1261295 4

Chemical analysis of the Bearing 1 by EDS using the beam@20 kV

Spectrum In stats. C O Al Si S K Sb at. % Spectrum 1 Yes 88.5 10.9 0.3 0.3 Spectrum 2 Yes 18.1 52.6 5.4 18.0 6.0 Spectrum 3 Yes 22.6 1.2 76.2

Spectrum In stats. C O Al Si S K Cr Ni Sb at. % Spectrum 1 Yes 99.5 0.5 Spectrum 2 Yes 86.7 12.8 0.2 0.3 Spectrum 3 Yes 73.3 14.6 0.4 0.2 0.8 10.7Spectrum 4 Yes 27.7 51.9 4.0 12.4 3.4 0.6

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Chemical analysis of the Bearing 2 by EDS using the beam@20 kV

Element Weight% Atomic% C K 55.76 69.33O K 28.43 26.54Al K 0.27 0.15Si K 2.08 1.11S K 0.66 0.31Cr K 1.12 0.32Fe K 0.77 0.21Ni K 5.33 1.36Sb L 5.58 0.68 Totals 100.00

Element Weight% Atomic% C K 61.73 74.60O K 24.30 22.04Al K 0.29 0.15Si K 1.93 1.00S K 0.51 0.23Cr K 0.92 0.26Ni K 3.82 0.94Sb L 6.51 0.78 Totals 100.00

Element Weight% Atomic% C K 59.10 72.38O K 26.16 24.05Al K 0.25 0.14Si K 1.94 1.02S K 0.64 0.29Cr K 0.80 0.23Ni K 4.26 1.07Sb L 6.85 0.83 Totals 100.00

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Chemical analysis of the Bearing 2 by EDS using the beam@20 kV

Spectrum In stats. C O Al Si K Cr Fe Ni Mo Sn at. % Spectrum 1 Yes 94.5 5.1 0.5 Spectrum 2 Yes 70.8 16.3 0.1 0.5 1.8 0.2 10.0 0.2 0.1Spectrum 3 Yes 37.8 52.5 0.1 1.6 0.2 1.2 0.5 5.6 0.3 0.1Spectrum 4 Yes 31.2 44.1 0.5 24.2

Spectrum In stats. C O Al Si S Cr Fe Ni Sb at. % Spectrum 1 Yes 93.4 5.9 0.4 0.2 0.1 Spectrum 2 Yes 54.3 40.8 0.1 1.4 0.1 0.5 0.2 2.2 0.3Spectrum 3 Yes 86.2 11.0 0.3 0.1 2.4Spectrum 4 Yes 78.9 15.2 0.1 0.4 0.1 0.2 5.0

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CONCLUSIONS

• The bearing 1 and 2 base material is carbon.• Bearing 1 – we can found at higher magnification particles that contains

following elements in amounts higher than 5 at.%: aluminium (Al), silicon (Si) and Antimony (Sb). Particle rich in antimony was found as well.

• Bearing 2 – contamination of Al, Si, Sb, Sn, and also Cr, Fe and Ni was found.

• The same elements were found in previous work EDMS1258256 except of particles containing higher amount of Si and Sb.

Note:• To obtain a leak-proof seal face product, the carbon graphite must be

impregnated, using low melting point metals or resins as impregnating agents. In the case of lead impregnated carbon the service temperature is limited to 200 °C, in the case of antimony to 500°C.