Innovative SiC/SiC composites for nuclear applications
21 NOVEMBER 2012
| PAGE 1CEA | 7 juin 2012
MINOS Workshop, Materials Innovation for Nuclear Optimized SystemsDecember 5-7, 2012, CEA – INSTN Saclay, France
C. Sauder, C. Lorrette, A. Michaux, L. Gélébart, E. Buet, S Poissonnet, A Coupé, J. Braun,
L Briottet, M. Zabiego, J.L. Séran, M. Le Flem,L. Chaffron
Developpment of refractory materials for pin cladding of 4th generation reactors
Focus on SiC/SiC composites :
CONTEXT
• R&D mostly driven by GFR fuel objectives (2004-2010)
• Recently extended to other applications : SFR & PWR
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France
� Refractory material (>> 1000°C)
� Irradiation resistance
� Low activation
� Neutron transparency
� Corrosion resistance
Issues: gastightness + mechanical properties + thermal properties
Matrix: protects the fiber and displys loadtransfer
Fibre: ensures the mechanical strenght
Interphase: bonding between fiber and matrix
2µm
WHAT IS A SIC/SIC COMPOSITE ?
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France
transfer
1µm
stress
(1) withoutinterphase
(1)(2)
(2) With interphase
Deflection of the cracks
���� SiC/SiC is a non brittle ceramic
WHICH SIC/SIC FOR NUCLEAR APPLICATION?
Choice of the fiber:
Stability under irradiation ⇒⇒⇒⇒
Hi-Nicalon S ou Tyranno SA3 fibers only
Stability at high temperature ⇒⇒⇒⇒
Tyranno SA3 fibers looks better
Thermal conductivity ⇒⇒⇒⇒
Tyranno SA3 fibers looks better
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France
Tyranno SA3 fibers looks better
Cost ⇒⇒⇒⇒Tyranno SA3 fiber is cheaper (30%)
HNS TSA3
Thermal stability
Thermal conductivity
Cost
Mechanical properties
Choice of the interphase: PyC
Choice of the matrix: SiC CVI
TSA TSA isis the the targettarget!!
THE MAIN CONCERNS FOR PIN CLADDING
FP retention= gas-thightness
Thermal exchange= High λ
Irradiation mechanical behavior
SiC/SiC is not gastight upon its linear elastic
domain.
λ SiC is lowered under irradiation (highly lowered at
low temperatures)
Strain to failure εR > 0,5%
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 5
domain. low temperatures)
Introduction of a liner for gas-tightness
=CEA sandwich concept
- Deal with it !- Use of SA3 reinforcement- Process a specific matrix
for composites⇒ very long term work
- Ok with HNS- No solutions with SA3- Look for high doseirradiated mechanicalbehavior.
Goal:� Development of a gastight component prepared from HNS SiC/SiCcomposite
D∼∼∼∼ 2.7-2.9 D∼∼∼∼ 2.8 – 2,9 D∼∼∼∼ 2.3-2.4
±±±
PROCESSING : INFLUENCE OF BRAIDING AND GRINDING
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 6
Filament Winding
2D braiding 3D braiding
With and without grinding
Grinded (machined) composite
Original composite
• Properties can be tailored thanks to appropriate braiding
• Grinding has no significant effect on CMC
CHARACTERIZATION: WHICH TEMPERATURE LIMITATION?
Influence of a thermal treatment (2h in Ar) on mechanicalproperties
HNS tube
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 7
CVI SiC/SiC tube is not sensitive to very high tempera turein inert atmosphere
HNS fiber
Reference SiC/SiC material for Pin cladding :
FW (45°) 1 layer + 2D braiding (45°) 2 layers
mechanical behavior is the same for traction or internal
CHARACTERIZATION : FATIGUE
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 8
same for traction or internal swelling
Fatigue tests:20 -200MPa at 5 HzNo failure after 500 000 cycles!
3 Patents :
⇒⇒⇒⇒ Control of dimensions and tolerances of CMC composi tes
CEA/LTMEx Products
External and internal dimensions within 0,01mm tolerance
CHARACTERIZATION : DIMENSIONNING
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 9
- external and internal dimensions: ±0.01 mm- external cylindricity < 0.03mm with mean value of 0.02 mm.- internal cylindricity < 0.05mm with mean value of 0.04 mm.- concentricity < 0.05mm with mean value of 0.04 mm- external Straightness < 0.02mm with mean value of 0.005 mm- internal Straightness < 0.04mm with mean value of 0.02 mm- Ra (mean roughness) < 5µm and Rz (max roughness) < 30µm
Very good dimensional accuracies (could be improved for internal part)
SiC/SiC CEA SiC CVD (R&H)
Purity of CEA SiC/SiCcomposites
CHARACTERIZATION: IMPURITIES CONCENTRATION
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 10
Very few impurities
Residual Impurities (Fe, S, N, O, H) belong to Hi-Nicalon S fibers
CEA | 21 Novembre 2012
Liquid Phase Process:Liquid Phase Process:
���� Hybrid Process CVI + EPI + PIP
Objective : Increase thermal conductivity of SiC f/SiC
by lowering porosity
Raw material
weaved Cf or SiC f
CVI Interphase PyC+ SiC Pre-densification
EPI + PIP SiC green Matrix
T°, P
ALTERNATIVE PROCESSING
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 11
Cf/ PyC/ SiC nano
t = 4 min
Cf/ PyC/ SiC nano + SiC Polymer
Cf/ PyC/ SiC/SiC nano + SiC Polymer
SiC nanopowderLTMEx pyrolysis
���� Processing of a SiC layer on composites
Objectives : Densification and smoothing of SiC f/SiC composites
Bubbles: Polymer/resin reactions
Raw material
This alternative process could be used for densification of hexagonal tubes (cf P David oral) for which requirements are less harsh
Sandwich concept (CEA Patent)
PROCESSING : « SANDWICH » CONCEPT
150
200
250
300
Con
train
te (
MP
a)
C. Sauder & C. Lorrette (CEA/DMN)
Leak-tight domainwith present-day CMC
Failure limit( σσσσF~300MPa - εεεεF~0,9%)
Str
ess
[M
Pa]
150
200
250
300
Con
train
te (
MP
a)
C. Sauder & C. Lorrette (CEA/DMN)
Leak-tight domainwith present-day CMC
Failure limit( σσσσF~300MPa - εεεεF~0,9%)
Str
ess
[M
Pa]
All stages of processare done in CEA
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 12
- Metallic liner only ensures tightness (processing in LTMEX)
- Composite ensures mechanical resistance
- Process is simple and reproducible
This type of cladding is supposed to be tight up to failure of the pin
Internal tube SiC/SiC: e~0.3mmliner Ta : e <0.1mmExternal tube SiC/SiC: e~0.6mm
0
50
100
0 0,2 0,4 0,6 0,8 1
Déformation (%)
Elastic limit( σσσσE~80MPa - εεεεE~0,04%)
Beginning of microcracking
Elongation [%]
Str
ess
[
0
50
100
0 0,2 0,4 0,6 0,8 1
Déformation (%)
Elastic limit( σσσσE~80MPa - εεεεE~0,04%)
Beginning of microcracking
Elongation [%]
Str
ess
[
Sandwich Concept – Choice of liner
1E-12
1E-11
1E-10
1E-09
1E-08
4.5E-04 5.0E-04 5.5E-04 6.0E-04 6.5E-04 7.0E-04 7.5E-04 8.0E-04 8.5E-04 9.0E-04 9.5E-04 1.0E-031/T(K-1)
-1)
Fe (Naka et al) Ni (Naka et al) Co (Naka et al)
Ti (Naka et al) V et Cr (Naka et al) Zr (Naka et al)
Mo (Naka et al) Nb (Naka et al) Ta (Naka et al)
Zr (Bhanumurthy et Schmid-Fetzer) Ni (Bhanumurthy et Schmid-Fetzer) Cr (Bhanumurthy et Schmid-Fetzer)
Nb (Naka et Feng) Mo (Yoon et al) W (Lee et al)
W (Kharatyan et al) Nb (Joshi et al) Mo (Kharatyan et al)
« SANDWICH » CONCEPT: WHICH LINER?
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 13
Tantalum and Niobium are the best candidates for GF R Is it still true for PWR or BWR ?
1E-18
1E-17
1E-16
1E-15
1E-14
1E-13
k(m
2 .s-1
1600°C 1400°C 1200°C 1000°C 900°C 800°C 750°C
Ta
Nb
Nb
Sandwich Concept – tightness during tensile test
SANDWICH CHARACTERIZATION: PERMEATION
150
200
250
300
350
400
F/S
o (M
Pa)
1.0E-08
1.0E-07
1.0E-06
1.0E-05
1.0E-04
1.0E-03
1.0E-02
Déb
it (N
cm3/
s)
pression relative Hélium : 2 bar fin acquisition spectro en continu
acquisition uniquement aux palliers
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | 14
Detection limit
« sandwich » concept allows to keep tightness up to failure of SiC/SiC pin cladding
0
50
100
0 2000 4000 6000 8000 10000 12000 14000
temps (s)
1.0E-11
1.0E-10
1.0E-09
1.0E-08
:
SiC
NbC
Nb5Si4C
NbCNb2C Nb
SiCTaC
Ta5Si4CTa5Si3TaSi2
Ta
Précipités Ta 2C
Sandwich Nb – 1000h – 1200°C – Sandwich Ta
0h
63h
250h
outer
Liner
Sandwich Ta1200°C
3. SANDWICH CHARACTERIZATION
inner
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 15
250h
560h
1000h
- Very encouraging results with Ta- Reaction zones are not symmetric
(not observed with plates)- Further characterization needed
inner
2. CHARACTERIZATION: IRRADIATION
0
200
400
600
800
1000
1200
0 0.2 0.4 0.6 0.8
Strain (%)
Ten
sile
Str
ess
(MP
a)
unirradiatedSample 1 (3.1 dpa)Sample 2 (3.1 dpa)
Very encourageing results have beingobtained with CVI minicomposite (CROCUS
irradiation performed in OSIRIS)
NEXT STEP:
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France | PAGE 16
⇒ Irradiation in BOR60 (sodium, 550°C up to 105-120 dpa SiC)
First irradiation of SiC/SiC composites at such dose s(Including sandwich specimens)
���� PIE are expected for 2015
NEXT STEP:
Irradiation Irradiation shouldshould startstart on on decemberdecember 19, 201219, 2012
CONCLUSION AND PROSPECTS
• CMC: Tailoring materials
• Current work focused on fabrication of gastight closed for fast
reactor applications (and hexagonal tube)
• Developpment of high skills in CMC manufacturing process at CEA
• Robust program of characterization: assessment of the high
quality of the composites made at CEA
• Pursuit of Investment for CMC development: deliveryof a winding
CEA – DEN MINOS Workshop - December 5-7, 2012, CEA – INSTN Saclay, France
• Pursuit of Investment for CMC development: deliveryof a winding
machine in the next days and investment of a braiding machine in
2013
• Collaborative work with french universities through Matinex and
NEEDs networks (Bordeaux, Mulhouse, Caen, Grenoble) and
industrial partners
| PAGE 17
Direction de l’Energie NucléaireDépartement des Matériaux pour le NucléaireService de Recherches Métallurgiques AppliquéesLaboratoire de Technologie des Matériaux Extrêmes
Commissariat à l’énergie atomique et aux énergies alternatives
Centre de Saclay | 91191 Gif-sur-Yvette Cedex
T. +33 (0)1 69 08 51 66| F. +33 (0)1 69 08 82 52
Etablissement public à caractère industriel et commercial | RCS Paris B 775 685 019
| PAGE 18
CEA | 7 juin 2012