1. Aluminum bellows for experiments
C. Garion & R. Veness, TE/VSC
C. Garion

2. Outline Development history 2 ways of procurement Development at CERN
Japanese company
CERN
Development at CERN
Material
Bellows parameters
Bellows manufacturing
Present situation and further actions
Conlusions
C. Garion

3. Development History Formed Bellows Machined Bellows
European industry R&D project ( )
Thick-walled aluminium bellows are made for cryogenic applications, but no standard production of thin-walled bellows in Europe
2 development projects were followed with European manufacturers, but neither successful results nor much interest
Machined Bellows
CERN Workshops ( )
Good results obtained for 0.3 mm thick bellows
Pieces installed in LHCb (small stroke)
Leaks during production and test linked to material form and quality
R.Veness
LEB 30 VII 09
C. Garion

4. Japanese Industry Background
Both Titanium and Aluminium bellows have been used in accelerator vacuum systems in Japan (TRISTAN and J-PARC)
They were produced by Japanese industry in large numbers following joint development projects with the labs
With help from KEK, a potential supplier was identified, and CERN issued a specification
R.Veness
C. Garion

5. Development Contract Prototype series Full series
Order placed in June ‘09 for a series of 3 bellows, as per the drawing opposite
Delivery expected end Oct ’09
Full series
An offer has been made for a series of 30 bellows
Unit Price ~ 1800 CHF/piece
3 months delivery
R.Veness
C. Garion

6. CERN development for formed bellows Material
Requirements:
Formability (high ductility)
Weldability (also with 2219)
Low Heat affected zone
Available in thin foils
Good mechanical properties
2 materials: series 5000 (Magnesium):
Well weldable
Good corrosion resistance
Mechanical properties acceptable
Non heat treatable
 5754 H22:
0.3mm thick
5083 H111, 0.2 and 0.3mm thick (available beginning of September)
0.2 and 0.3 mm thick
C. Garion

7. Design Algorithm of optimization of bellows expansion joints (Based on EJMA)
Minimise the objective function:
inequality constraints:
bellows convoluted length
inner diameter
outer diameter
bellows maxi compression
membrane stress
membrane & bending stress
fatigue life
column buckling
in-plane squirm
Atlas constraints (technical specification EDMS ):
Lbmax = 100 mm
Dmin ~ 60 mm
Dmax = 80 mm
Stroke = -24/+8mm
Nf > 500 cycles
C. Garion

8. Design Bellows parameters
Thickness 0.2 mm
Thickness 0.3 mm
Design has to be compatible with formability capacity
Other wish: if possible use the same tooling:
0.3mm thick: 13 convolutions, bellows length: ~96mm, Inner diameter: 60 mm, outer diameter: 78.8mm
0.2mm thick: 8 convolutions, bellows length: ~59mm, Inner diameter: 60 mm, outer diameter: 78.8mm
C. Garion

9. Bellows manufacturing (courtesy of L. Prever Loiri, EN/MME)
Aluminum foil
Rolled tube & longitudinal weld (EB)
Welds of the end fittings (EB)
Cut of the end fittings
combining pressure and displacement loading
C. Garion

10. Present situation 2 materials have been chosen:
5754 has been received, metallurgical and mechanical tests have been done (EN/MME)
5083 has been ordered. Delivery is expected beginning of September
Metallurgical observations (grain size, inclusions)
Tensile test at room temperature
Bellows parameters have been defined and optimized
Welding procedure has been determined
C. Garion
Micrograph of longitudinal weld

11. Present situation
Tooling (forming and welding) have been designed and manufactured (EN/MME)
Tubes are equipped with the end fittings
 First tube equipped with the end fittings is ready for forming
Analysis is being done to optimize the forming process (pressure-displacement function)
C. Garion

12. Forming simulation
Mesh
Mesh
Deformed shapes
Pressure
Displacement
Plastic strain after forming
Further detailed FE analysis will be done (A. Sarrio Martinez)
C. Garion

13. Next steps Forming tests on 5754 tube: As assembled
After heat treatment (annealing)?
Qualification tests:
Leak tightness
Fatigue life a room temperature
Stability?
Reception of 5083 and metallurgical tests
Welding tests
Forming
Qualification:
Leak tightness
Fatigue life a room temperature
Stability?
C. Garion

14. Tentative schedule (Alba Sarrio)
End of prototyping: 12/09
First bellows by August 2009
Series
C. Garion

15. Conclusions
An order has been placed to a Japanese company for aluminum bellows prototypes
Development of aluminum bellows at CERN is well advanced:
2 Material chosen: 1 delivered and 1 available beginning of September
Forming process at “high” temperature will be used
Bellows parameters are defined
Welding process are defined
Tooling for forming are ready
Forming process will probably not be straight forward. Iterations might be necessary.
C. Garion