materials for phase ii collimators
DESCRIPTION
Materials for Phase II collimators. Rib Stiffener, why molybdenum. Stiffener material requirements: Minimise own thermal distortion Low CTE High thermal conductivity Minimise deflection by the force in the midpoint link High Young’s modulus. X-deflection simulation. - PowerPoint PPT PresentationTRANSCRIPT
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 1
Materials for Phase II collimators
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 2
Rib Stiffener, why molybdenum
Active part where most of heat is deposited tends to deflect due to thermal gradient Stiffener linked in a midpoint
to limit deflection of the active part
X-deflection simulation
Stiffener material requirements:Minimise own thermal distortion
Low CTE High thermal conductivity
Minimise deflection by the force in the midpoint link
High Young’s modulus
Shafts, fixed points
Link
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 3
Stiffener, why molybdenum
Thermal conductivity / Thermal expansion coefficient -15 -10 -5 0 5 10 15 20 25 30 35 40 45 50 55
You
ng's
mod
ulus
(G
Pa)
0
50
100
150
200
250
300
350
400
450
500
550
Tungsten (f)
Iridium, Commercial Purity, min 99.9%, softOsmium, Commercial Purity, soft
Ruthenium, Commercial Purity, soft
Rhenium, Commercial Purity, soft
Rhodium, Commercial Purity, hard
Molybdenum, 360 grade, wrought, stress relieved
Nickel-Iron Alloy, "INVAR", hard (cold worked)
Nickel-Iron Alloy, "INVAR", soft (annealed)
Wrought PH stainless steel, Custom 455, H1000
Wrought austenitic stainless steel, AISI 304, annealed
Tungsten, Commercial Purity, annealed
Tungsten, Commercial Purity, 25 micron wire
Al-C-fiber composites
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 4
Stiffener made of Mo, old monolithic version
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 5
Stiffeners made of Mo, assembled by bolts and pins
• How are the stiffners
Long plates 15 x 47 x 1100 mm³ Thinner extremities Circular holes and slots Tolerance ~0.1 mm Threaded holes for cooling clamps
Spacers
Positioning system
Bolts and pins
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 6
Stiffener, raw material• Overall dimension of long plate (mm)
– ≥15 x 47 x 1100
• Standard dimensions by Plansee– 12.7 x 500 x 600– 20 x 500 x 600
• Possibility of having customized production
• Ideas to make it out of standard dimension plate for prototypes (4÷8 plates), eventually for series (~250 plates)
– EB butt weld
– Connect overlapped plates, bolted or riveted
• Also– Spacers– Positioning system– Bolts and pins
EBW EBW
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 7
Stiffener, machining
• Recommended machining parameters
• Plansee as possible supplier of finished components– Tolerances achievable
• Extremity holes
• Positioning system elements
– Do you see any other issue
not mentioned?
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 8
Cooling coil, interest of using molybdenum
Phase 1, implemented solution: Phase 2, increased energy deposition.-Cooling capacity has to be increased
- 6 x tubes ID8 mm- reduce contact thermal resistance
-Geometrical stability has to be maintained- use material with optimised k/CTE
Ideal solution:Cooling coil back-casted in M-CD block
C-C
GlidCop
CuNi
BrazingBrazingContact
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 9
Cooling coil, interest of using molybdenum
• Cooling coil material for Ideal solution requires
– Metallurgical compatibility with metal of the block• Avoid dissolution of the coil in the liquid metal• Avoid inconvenient inter-metallic phases at the interface
– CTE matching with M-CD• Avoid distortion, residual stresses or debonding at the interface when
solidifying and cooling from infiltration temperature• Gaps at the interface leads to poor thermal conduction and virtual leaks
– Feasibility of the coil
• Cooling coil materials believed to be good candidates from the first two points of view
– For Cu-CD: molybdenum, niobium, tantalum– For Al-CD: zirconium (preliminary test program is in progress in
cooperation with L. Weber EPFL including also stainless steel)
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 10
Cooling coil, interest of using molybdenum
• Molybdenum coil in Cu-CD block– CTE– Phase diagram– Feasibility of the coil
Thermal expansion coefficient (µstrain/°C)-15 -10 -5 0 5 10 15 20 25 30 35 40
The
rmal
con
duct
ivity
(W/m
.K)
0
50
100
150
200
250
300
350
400
Silver, Grade 99.90, cast bar, hard (cold worked)
Antimony metal, Commercial Purity, "Regulus"
Gold, Commercial Purity, min 99.5%, hard (cold-worked)
Niobium, Type 2 (Commercial Grade Unalloyed Niobium)
Rhenium, Commercial Purity, soft
Hafnium, Commercial Purity, min 97.0%
Osmium, Commercial Purity, hard
Carbon steel, AISI 1015 (annealed)
Zirconium, Unalloyed, Industrial Grade, wrought, "Zr702"
Nickel-Iron Alloy, "INVAR", soft (annealed)
Unalloyed titanium, Annealed
Tantalum, Commercial Purity (>99.7% Ta), cold worked
Electrolytic tough-pitch, h.c. copper, soft (wrought) (UNS C10100)
70/30 Copper-nickel, CuNi30Mn1Fe, soft (wrought) (UNS C71500)
Wrought aluminum alloy, 5052, O
Wrought aluminum alloy, 5086, O
Wrought ferritic stainless steel, AISI 430, annealed
Nickel 205, Commercial Purity, annealed
Cobalt, Commercial Purity, soft (annealed)
Molybdenum, 360 grade, wrought, stress relieved
Iridium, Commercial Purity, min 99.9%, hard
Ruthenium, Commercial Purity, soft
Rhodium, Commercial Purity, hard
Tungsten, Commercial Purity, annealed
Cu-CDAl-CD
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 11
Cooling coil, interest of using molybdenum
Liquid Cu would dissolve Ti or Zr tube !
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 12
Cooling coil, interest of using molybdenum
Mo, Nb and Ta have limited solubility in liquid Cu and do not form inter-metallic phases
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 13
Cooling coil, interest of using molybdenum
• Feasibility of long intricate coil is a question mark.– ID 8 mm x L 3800 mm– Bending radius as small as 18 mm
• Tests and trials– Tensile test at RT on molybdenum tube OD10xID8 (our CA1491024)
• Rp0.2 = 570 MPa Rm = 685 MPa• A ≥ 40% !!! but transversally very low ductility• Inner wall of the tube is oxidised
– Bending tests to be done at CERN workshop• What are your recommendations?
– Butt welding, your recommendations
LHC Collimators Phase 2 - Visit to Plansee 28th August 2008 14
• Avoid virtual leaks (confined volumes with low aperture that make long time to evacuate)
• Avoid any welding or brazing between water and beam vacuum ! use of continuous seamless tube
• Other solutions if the last constrain can be relaxed:– Cooling circuit machined in a block, closed by brazing or welding
• Brazed to the main block• Back-casted inside the main block
– Any other? – Any experience in similar large surface brazing
Cooling coil, vacuum related constrains