Global review & lessons learnt on the HIPingmethods state of the art, including R&D, applicability, prototype and tests

HL-LHC Collimators: Design, Engineering and Prototyping #29

Inigo Lamas Garcia EN-STI-TCD

Presentation courtesy of Antonio Perillo-Marcone EN-STI-TCD

Background

• Several dumps need to manage significant thermal power

• “Efficient” and if possible “quantifiable” thermal contact

between cooling pipes and core is required

• Some BIDs are meters long

• Several BIDs are in UHV

• Many techniques are not acceptable

• TE-VSC “forbids” welded connections (water-vacuum barrier) inside

vacuum

2

Previously used techniques

3

• Dédudgeonage

• Used for TED

• Not compatible with UHV

• Specific tooling required for each tube diameter

• Only straight tubes

• Efficiency unknown

• Very long process

• Issues encountered

Previously used techniques (2)

21/01/2019 A. Perillo-Marcone - TCD Extended Section Meeting #13 4

• Brazing

• Used for Collimators

• Compatible with UHV

• Quality highly dependant on supplier

• Good thermal efficiency

Previously used techniques (3)

• Clamping

• Used for TIDVG#4

• Compatible with UHV

• Sensitive to machining precision

• Dependent on contact pressure

• Efficiency low (unquantifiable)

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Heat transfer through interface

6

Mechanical contact Brazing Diffusion bonding

Diffusion Bonding by HIP

• Hot Isostatic Pressing (HIP)

• To be used for TIDVG#5 and PS Internal Dump

• Compatible with UHV

• Some sensitivity to tolerances

• Versatile – different geometries possible

• Reproducible

• Maximum thermal efficiency (diffusion

bonding all around the tube – perfect contact)

7

HIP – Preliminary tests

8

Diffusion bonding between stainless steel

and cuprous materials

CuCrZr – Special Case

• Materials properties highly dependent o thermal treatments

• After HIP, both mechanical and thermal properties badly

degraded

• Additional thermal treatments needed

• Solution annealing (920 °C / 20 min) – water quenching

• Aging (480-500 °C / 2 h)

9

Detailed analyses on samples

10

Fraunhofer IFAM

CERN – EN/MME-MM

• Penetrant Testing (PT)• Optical Microscopy (OM)• Scanning Electron Microscopy (SEM)

Optical Microscopy

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• No discontinuities at tube/Cu interface

• Some discontinuities at witness/Cu and

Cu/Cu interfaces

• No defects detected by PT

• Crossing grains observed at Cu/Cu interface

DS-Cu

CuCrZr

OF-Cu

OF-Cu

Thermal conductivity

12

From the thermal point of view the bonding is “PERFECT”

Principle validated.Full prototypes launched

TIDVG#5 core

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Seamless tube inside vacuum

2500mm-long plate

Full scale TIDVG#5 cooling plate

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1

2

Prototype - encapsulation

15

SS capsule

Pumping tube

Capsule – tubes weld

Stiffener

SS wool

HIP Process

16

Thermal treatments after HIP

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Hardness (HB) Stage

45 After HIP

60 HIP + solution annealing

108 HIP + solution annealing + aging @ 500°C

Further Characterisation

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SS

CuCrZr CuCrZr CuCrZr

SEM Images

CuCrZr

CuCrZr/CuCrZr Interface

CuCrZr/SS Interface

Thermal tests on prototype (La Plancha)

19

Tests ongoing…

PS Internal Dump

20

F.X. Nuiry, G. Romagnoli, B. Fischer

First Prototype

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AFTER HIPBEFORE HIP

Pressure test

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1 23

4

Pressure test with water

22 bar for 1 h

Tube 1 -3 -4 showing no pressure leak

TUBE 2 impossible to rise pressure but deformation of the capsule

Oxidation of Stainless Steel

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OXIDATION OF TUBES:XPS analysisEDMS 1977034

Inside of tube

• The inside of the tube is strongly oxidized

• Grey-green appearance (chromium oxide) → Formed during HIP or thermal treatments

It could have an influence on heat efficiency !

Prototypes of Alumina Coatings

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8 assemblies:

3 x plasma deposition Alumina coating of 0.10 mm ✓

1 x plasma deposition Alumina coating of 0.15 mm ✓

2 x plasma deposition Alumina coating of 0.20 mm ✓

2 x Alumina coating with brush (like previous test) ✘

~50 mm

30 mm

~110 mm

70 mm

42 mm

Alumina-coated CuCrZr(no bonding)

Non-coated CuCrZr (bonding)

Next prototype – Protective blocks

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A A

A –A

Ti (Gr2) CuCrZr BN

316L Tubes

(ID15 / OD18)

Alumina tube

(ID18.5 / OD30)

Alumina coating

(brushing)

Alumina plate

(1mm thick)

100 100 100

100

60

60

Conclusions

• Diffusion bonding is ideal for thermal management under vacuum

• Excellent results obtained between SS and cuprous materials

• Large dimensions possible (~ 1 m x 3 m)

• Initial geometry (gaps) very important

• Prototyping vital to tune up the process

• Benefits from avoiding the use of Glidcop

• Increased number of companies able to produce collimators if brazing is no

longer needed

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Documents

• EDMS 1838803

• EDMS 1805777

• EDMS 1977033

• EDMS 1985623

• Others to come soon …

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Thank you for your attention.