Aluminum bellows for
experiments
C. Garion & R. Veness, TE/VSC
C. Garion
LEB 30 VII 09
Outline
• Development history
• 2 ways of procurement
 Japanese company
 CERN
• Development at CERN




Material
Bellows parameters
Bellows manufacturing
Present situation and further actions
• Conlusions
C. Garion
LEB 30 VII 09
Development History
•
Formed Bellows
– European industry R&D project (1999-2001)
• 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 (2001-2006)
• 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
C. Garion
LEB 30 VII 09
LEB 30 VII 09
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
LEB 30 VII 09
Development Contract
•
Prototype 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
LEB 30 VII 09
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
LEB 30 VII 09
Design
Algorithm of optimization of bellows expansion joints
(Based on EJMA)

•Minimise the objective function: Fax ( x bl ) 
Cf
•inequality constraints:
bellows convoluted length
inner diameter
outer diameter
bellows maxi compression
3

 t p   n p  

   
 E T d m  w   n  
   c 

Lmax  Lbl  0
Din  Dmin  0
Dmax  Dout  0
 bl   min  0
Atlas constraints (technical
specification EDMS 429891):
Lbmax = 100 mm
Dmin ~ 60 mm
Dmax = 80 mm
Stroke = -24/+8mm
membrane stress
membrane stress
membrane & bending stress
Sad  S1  0
Sad  S2  0
S34  (S3  S4 )  0
fatigue life
Nf (St )  Nf 0  0
column buckling
in-plane squirm
Pcol  P1  0
Pinp  P2  0
C. Garion
Nf > 500 cycles
LEB 30 VII 09
Design
Bellows parameters
Thickness 0.2 mm
Thickness 0.3 mm
100
100
Stiffness
20
3
7
10
11
Number of
convolutions
Bellows
length
0
15
90
19
60
15
80
Number of
convolutions
30
70
11
40
55
7
50
40
3
40
90
80
70
60
50 Stiffness
40
30
20
10
0
Bellows
length
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
LEB 30 VII 09
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
Forming @150°C combining pressure
and displacement loading
C. Garion
LEB 30 VII 09
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
LEB 30 VII 09
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
LEB 30 VII 09
Forming simulation
Mesh
Mesh
Deformed shapes
Pressure
Displacement
Plastic strain after forming
Further detailed FE analysis willC.be
done (A. Sarrio Martinez)
Garion
LEB 30 VII 09
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
LEB 30 VII 09
Tentative schedule
(Alba Sarrio)
First bellows by
August 2009
C. Garion
End of
prototyping:
12/09
Series
LEB 30 VII 09
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
LEB 30 VII 09