Phase 2 Outer Tracker Mechanics meeting, 21 May 2014
Thermally conductive carbon-fibre composite
material for module and mechanics prototyping
Outer Tracker Mechanics, indico: 316581
1
21 May 2014, A.Onnela
The need
Thermally conductive carbon-fibre composites needed for
• 2S and PS modules
• Module support surfaces in the TIB
• TEC Dees in the PS module areas
Outer Tracker Mechanics, indico: 316581
2
21 May 2014, A.Onnela
Carbon-fibre composites in the 2S modules
•
•
0.5 mm thick carbon-fibre composite
support / heat-spreaders under the hybrids
0.5 mm thick hybrid fold-over supports
thermally less important
Note: All carbon-composite thicknesses are
preliminary. Significant changes possible
following further design work and prototyping.
Outer Tracker Mechanics, indico: 316581
3
21 May 2014, A.Onnela
Carbon-fibre composites in the PS modules
Attention: These
on the sensor
spacers model
Parylene coating,
not C-fibre!
•
•
•
0.2 mm thick module base-plate
0.2 mm thick support / heat-spreaders under
all hybrids
0.2 mm thick hybrid fold-over supports
thermally less important.
Note: All carbon-composite thicknesses are
preliminary. Significant changes possible
following further design work and prototyping.
Outer Tracker Mechanics, indico: 316581
4
21 May 2014, A.Onnela
TIB flat module support plates
•
•
0.5 mm thick carbon-fibre skins for module
support and structural stiffness
Foam core, in carbon foam?
Note: All carbon-composite thicknesses are
preliminary. Significant changes possible
following further design work and prototyping.
Outer Tracker Mechanics, indico: 316581
5
21 May 2014, A.Onnela
TIB tilted module support rings
Module support / cooling contacts need to be studied.
•
•
•
Outer Tracker Mechanics, indico: 316581
Aluminium / carbon-fibre composite?
Carbon-fibre / polymer composite?
Aluminium?
6
21 May 2014, A.Onnela
TEC module support Dees
TEC Dee skins in carbon-fibre composite
• Skins with high thermal conductivity in the inner rings with PS modules.
Dee structure with 0.5 mm
carbon-fibre skins
Note: All carbon-composite thicknesses are
preliminary. Significant changes possible
following further design work and prototyping.
Outer Tracker Mechanics, indico: 316581
7
21 May 2014, A.Onnela
Requirements
Key requirements for the needed thermally conductive carbon-fibre composites
• High thermal conductivity
–
Fibres with very high thermal conductivity: > 600 W/mK
•
•
•
Thermal stability
–
•
CTE close to that of silicon: 2.6 ppm/K
Stiffness
–
Fibres with high tensile modulus: > 600 GPa
•
–
–
•
High fibre content in the composite: > 60% in mass.
Unidirectional, long fibres rather than weaves and chopped fibers.
HL-LHC dose in CMS Tracker: ~1 MGy @ 20 cm, after 3000 fb-1
Possibility to obtain thin laminates, down to 0.2 mm total thickness
–
•
Standard modulus fibres 230 – 350 GPa, steel 210 GPa, aluminium 70 GPa.
Radiation resistance
–
•
Standard modulus fibres 20 – 200 W/mK, copper 400 W/mK, aluminium 210 W/mK.
Transverse thermal conductivity dominated by the resin (conductivity ~ 0.1 – 0.2 W/mK). Can be accepted if the composite
pieces are thin and if the fibres can be oriented along the dominating heat path.
Requires high-quality thin prepregs, in 0.05 – 0.07 mm thickness.
Suitable processing properties
–
Low temperature curing: max 130 C
•
–
Many resin systems require 170 – 180 C, leading to higher residual stresses.
High-precision components with flatness of ~50 µm over 100 mm.
Outer Tracker Mechanics, indico: 316581
8
21 May 2014, A.Onnela
Past experience?
Apart from the higher radiation levels and aim for thinner laminates the requirements for the thermally
conductive composite materials are identical with the current Tracker.
Composite material used for the module frames of the current Tracker were:
• Fibre: Mitsubishi type K13D2U;
• Resin: YLA Cyanate Ester CE3 (RS3);
• Unidirectional pre-preg with 125 um nominal thickness;
• Four layer lay-up [0o/90o/90o/0o] for 0.5 mm total thickness.
–
•
Used in the TIB and TID modules.
Five layer lay-up [0o/90o/0o/90o/0o] for 0.63 mm total thickness.
–
Used in the TOB and TEC modules.
•
Successful production of the module frames, and of the modules in the required quality.
•
The old specification documents available in https://espace.cern.ch/TrackerUpgrade/mechanics/SitePages/Home.aspx - Documents - Existing Tracker's Design Parameters, Specifications and
other Documents
Outer Tracker Mechanics, indico: 316581
9
21 May 2014, A.Onnela
Mitsubishi K13D2U
Mitsubishi high-performance fibers (represents the state-of-the-art available today)
Outer Tracker Mechanics, indico: 316581
10
21 May 2014, A.Onnela
Reuse the same composite material again?
•
Good experience from the current Tracker. Reuse?
– Yes, the first 2S module prototype hybrids use exactly the
same material K13D2U/CE3, cut from spare laminate
pieces produced in December 2001.
– But no, the same composite material cannot be procured
anymore, as the resin system YLA Cyanate Ester CE3 (RS3)
is not produced anymore. The company YLA does not
exist anymore, bought by TenCate in 2008.
•
What choice to be made?
– Fibres: The Mitsubishi K13D2U still a good choice.
– Resin system: Three alternative producers:
• TenCate: Known, radiation tested products. Produces thin
prepregs.
• Renegade: New company, no radiation tested products.
• Hexcel: Known, radiation tested products. Thin prepregs not
in base-line production.
 TenCate preferred. Cyanate ester resin system EX-1515.
Proven radiation resistance, low temperature 127C cure.
Outer Tracker Mechanics, indico: 316581
11
21 May 2014, A.Onnela
TenCate EX-1515
Further info:
• https://espace.cern.ch/TrackerUpgrade/mechanics/SitePages/Home.aspx Documents - Materials
• http://www.tencate.com/emea/aerospacecomposites/def_prod/prepregs_list/default.
aspx
Outer Tracker Mechanics, indico: 316581
12
21 May 2014, A.Onnela
Purchasing prepreg material for prototyping
Main objectives:
• Allow testing the manufacture of thin laminates in 0.2 – 0.5 mm thickness.
– The 0.2 mm thickness is very challenging, not sure we will succeed.
– What is the exact, thinnest laminate thicknesses we should use in the modules and in the
structures matching manufacturability, flatness requirements, thermal performance? What is
the cost?
•
Provide laminates to be used for the 2S and PS module prototyping, as well as for the
development of the TIB and TEC support/cooling structures.
– What are the exact dimensions to be used in each part? Optimisation on manufacture, thermal
performance, and total mass.
Outer Tracker Mechanics, indico: 316581
13
21 May 2014, A.Onnela
Purchasing prepreg material for prototyping
A shared purchase order being placed right now.
• K13D2U / EX-1515 prepreg from TenCate
– 67% Carbon fibre and 33% Cyanate Ester resin (mass percentage)
– In rolls of 6” width
– Delivery in 3 different prepreg thicknesses to enable studying different laminate thicknesses and
layouts:
Fiber Areal Weight FAW of 45, 80, and 120 g/m2, corresponding to about 45, 80, 120 µm of
cured ply thickness.
•
•
For CMS Tracker Phase 2 Upgrade project, ALICE ITS development, and Linear Collider
Detector development.
Client users within CMS Tracker:
Known: CERN and DESY.
Still some ‘spare’ material possible to share. Others interested? Lyon?
Outer Tracker Mechanics, indico: 316581
14
21 May 2014, A.Onnela