10/25/2012

National Aeronautics and Space Administration

Integration Science and Technology of Advanced
Ceramics for Ene...
10/25/2012

National Aeronautics and Space Administration

Ever Increasing Global Energy Demand….

Source: US DOE
www.nasa...
10/25/2012

National Aeronautics and Space Administration

Critical Role of Advanced Ceramic Technologies
in Energy System...
10/25/2012

National Aeronautics and Space Administration

Overview of Key Ceramic Integration Technologies
Joining Techno...
10/25/2012

National Aeronautics and Space Administration

Integration of Metals to Ceramics and Composites
Using Metallic...
10/25/2012

National Aeronautics and Space Administration

Wettability is Important Factor in Integration
of Ceramics to M...
10/25/2012

National Aeronautics and Space Administration

Integration Technologies for Improved
Efficiency and Low Emissi...
10/25/2012

National Aeronautics and Space Administration

Integration Technologies for Silicon Nitride
Ceramics to Metall...
10/25/2012

National Aeronautics and Space Administration

Si3N4 (NT 154) bonded to Inconel 625 at 1317 K for 30 min
EDS d...
10/25/2012

National Aeronautics and Space Administration

TEM Analysis Silicon Nitride/Silicon Nitride Joints
Using Cu-AB...
10/25/2012

National Aeronautics and Space Administration

Kyocera SN-281 Si3N4 bonded at 1317 K for 5 min using
Cu-ABA (9...
10/25/2012

National Aeronautics and Space Administration

Kyocera SN-281 bonded at 1317K for 30 min.
(5 µm thick Cu foil ...
10/25/2012

National Aeronautics and Space Administration

Typical Shear Behavior of Multilayer Joints at
Different Temper...
10/25/2012

National Aeronautics and Space Administration

Integration Technologies for MEMS-LDI Fuel Injector
Objective: ...
10/25/2012

National Aeronautics and Space Administration

Leak Test of SiC Laminates Joined
with Silicate Glass
Combustio...
10/25/2012

National Aeronautics and Space Administration

Diffusion Bonding with 20 µm Ti Foil at 1200ºC
4 hr hold

1 1 h...
10/25/2012

National Aeronautics and Space Administration

Fractions of Phases in Each Sample
TiSi2

10 μm

Ti5Si3Cx

Ti3S...
10/25/2012

National Aeronautics and Space Administration

Fractions of Phases in Each Sample
TiSi2
In the sample 3, micro...
10/25/2012

National Aeronautics and Space Administration

High Strength of Bonds Greatly Exceeds
the Application Requirem...
10/25/2012

National Aeronautics and Space Administration

Detail of the Thickest Injector Substrate
(~0.635 cm thick)

Ai...
10/25/2012

National Aeronautics and Space Administration

www.nasa.gov

National Aeronautics and Space Administration

Ce...
10/25/2012

National Aeronautics and Space Administration

Integration of YSZ/Steel for SOFC Applications
• Gold-ABA and G...
10/25/2012

National Aeronautics and Space Administration

Transmission Electron Microscopy of As-Received
and Oxidized Fo...
10/25/2012

National Aeronautics and Space Administration

Integration of YSZ/Steel for SOFC Applications

• Structural ch...
10/25/2012

National Aeronautics and Space Administration

Transmission Electron Microscopy of
Interfaces in YSZ/Ag-Cu-Pd/...
10/25/2012

National Aeronautics and Space Administration

Concluding Remarks
• Ceramic integration technologies are criti...
Upcoming SlideShare
Loading in …5
×

Integration science and technology of advanced ceramics for energy and environmental applications.

484 views

Published on

Palestra plenária do XI Encontro da SBPMat (Florianópolis, setembro de 2012). Palestrante: Mrityunjay Singh - Instituto Aeroespacial de Ohio, ligado ao Centro de Pesquisa Glenn da NASA (EUA).

Published in: Technology, Business
0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total views
484
On SlideShare
0
From Embeds
0
Number of Embeds
0
Actions
Shares
0
Downloads
5
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

Integration science and technology of advanced ceramics for energy and environmental applications.

  1. 1. 10/25/2012 National Aeronautics and Space Administration Integration Science and Technology of Advanced Ceramics for Energy and Environmental Applications M. Singh Ohio Aerospace Institute NASA Glenn Research Center Cleveland, Cleveland OH 44135 www.nasa.gov National Aeronautics and Space Administration Outline • Introduction and Background g g • Technical Challenges in Integration – Similar vs Dissimilar Systems • Ceramic Integration Technologies – – – – Wetting and Interfacial Effects Ceramic-Metal Systems Ceramic-Ceramic Systems Testing and Characterization • Concluding Remarks www.nasa.gov 1
  2. 2. 10/25/2012 National Aeronautics and Space Administration Ever Increasing Global Energy Demand…. Source: US DOE www.nasa.gov National Aeronautics and Space Administration Advanced Materials and Technologies Play a Key Role in Improving Energy Efficiency Global Energy Efficiency 10,000 9,000 BT TU/$1,000 GDP 8,000 7,000 6,000 5,000 4,000 3,000 2,000 1,000 0 1975 1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 Source: Millennium Project, 2020 Global Energy Delphi Round 2 www.nasa.gov 2
  3. 3. 10/25/2012 National Aeronautics and Space Administration Critical Role of Advanced Ceramic Technologies in Energy Systems Energy Production Energy Storage and Distribution • Fuel Cells • Thermoelectrics • Photovoltaics • Nuclear Systems • Wind Energy • Biomass • Batteries • Supercapacitors • Hydrogen Storage Materials • Thermal Energy Storage/PCMs • High Temperature Superconductors Energy Conservation and Efficiency • Ceramic Components (Gas Turbines) • Heat Exchangers and Recuperators • Coatings, Bearings www.nasa.gov National Aeronautics and Space Administration Ceramic Integration Technologies: From Macro to Nanoscale A wide variety of integration technologies are needed for manufacturing and application of components of different length scales www.nasa.gov 3
  4. 4. 10/25/2012 National Aeronautics and Space Administration Overview of Key Ceramic Integration Technologies Joining Technologies • Ceramic-Ceramic • Ceramic-Metal Component & System Level Integration Repair/Refurbishment • In-Situ Repair • Ex-Situ Repair Mechanical Fastening • Ceramic-Ceramic • Ceramic-Metal • Rivets/Bolts Robust Manufacturing • Large Components • Complex Shapes • Multifunctional www.nasa.gov National Aeronautics and Space Administration Technical Challenges in Integration of Ceramic-Metal vs Ceramic-Ceramic Systems Ceramic-Metal System Ceramic-Ceramic System • Flow and wettability • Reaction and diffusion • Roughness • Roughness • Residual stress (∆CTE) • Multi-axial stress state • Joint design Common Issues • Residual stress (∆CTE) • Multi-axial stress state • Joint design • Joint stability in service • Joint stability in service • Metal – forgiving • Ceramic – unforgiving • Elastic-plastic system • Elastic-elastic system • Lower use temperatures • Higher use temperatures • Less aggressive environment • More aggressive environment www.nasa.gov 4
  5. 5. 10/25/2012 National Aeronautics and Space Administration Integration of Metals to Ceramics and Composites Using Metallic Interlayers Metallic Systems: • Titanium • Inconel and Other Ni-Base Superalloys • Kovar, Cu-Clad Mo, • Stainless Steels, W Active Metal Brazing Soldering Ceramics/Composite Systems: • SiC, Si3N4 , • YSZ, Alumina • C/C Composites • C/SiC, SiC/SiC Interlayer Systems: • Active Metal Brazes (Ag, Cu, and Pd based) • Metallic Glass Ribbons • Solders (Zinc based) ( ) Technical Issues: • Melting range / behavior • Wetting characteristics • Flux or atmosphere compatibility • Compositional compatibility • Cost & availability www.nasa.gov National Aeronautics and Space Administration Wetting and Interfacial Phenomena in Ceramic-Metal System y g Key Challenges: - Poor Wettability of Ceramics and Composites: (poor flow and spreading characteristics) - Surface Roughness and Porosity of Ceramic Substrates - Thermoelastic Incompatibility www.nasa.gov 5
  6. 6. 10/25/2012 National Aeronautics and Space Administration Wettability is Important Factor in Integration of Ceramics to Metals Young’s equation sv-sl = lvcos  Contact angle of braze should be small Braze layer melts and spreads between the substrates to form the joint Ordinary braze alloys wet the metal but not the ceramic systems Must use ‘active’ brazes that wet and bond with both metal and ceramics www.nasa.gov National Aeronautics and Space Administration Representative Joints in Various Systems SiC-SiC/Cu-clad-Mo C-SiC/Inconel 625 C-C/Cu-clad-Mo Self-joined UHTCC C-C/Ti Silicon nitride Cu-ABA SiC-SiC/braze/Si-X/Inconel (X: B, Y, Hf, Cr,Ta, Ti) Tungsten Si3N4/Ni/W/Inconel ZS Palco Tantalum Cu-ABA Inconel 300um 1(e) Nickel Si3N4/W/Ta/Inconel Foam/CMC Tungsten www.nasa.gov 6
  7. 7. 10/25/2012 National Aeronautics and Space Administration Integration Technologies for Improved Efficiency and Low Emissions • Gas Turbine Components www.nasa.gov National Aeronautics and Space Administration Advanced Silicon Nitride Based Components for Energy and Aerospace Systems Issues with Inserted Ceramic Blades Hybrid Gas Turbine Blade (Ceramic Blade and Metallic Disk) in NEDO’s Ceramic Gas Turbine R&D Program, Japan (1988-1999) There are contact stresses at the metal -ceramic interface. Compliant l C li t layers (i (i.e. Ni-alloy+Pt) are used to mitigate the stress and damage. Failures can occur in the compliant layer. Mark van Roode, Solar Turbines www.nasa.gov 7
  8. 8. 10/25/2012 National Aeronautics and Space Administration Integration Technologies for Silicon Nitride Ceramics to Metallic Components Industry Direction INTEGRAL ROTORS • No Compliant Layer with Disk •A Attachment of Ceramic R h fC i Rotor to Metal Shaft • Primarily Small Parts • Ability to Fabricate Larger Parts Has Improved • Integral Rotors are Replacing Metal Disks with Inserted Blades IR Silicon Nitride Rotor Rotor, DOE Microturbine Program (top) H-T. Lin, ORNL Mark van Roode, Solar Turbines www.nasa.gov National Aeronautics and Space Administration Integration of Silicon Nitride to Metallic Systems Approach: Use multilayers to reduce the strain energy more effectively than single layers. Challenge: Multiple interlayers increase the number of interfaces, thus increasing the probability of interfacial defects. Material CTE ×106/K Silicon nitride Inconel 625 Ta Mo Ni Nb Kovar W 3.3 13.1 6.5 4.8 13.4 13 4 7.1 5.5-6.2 4.5 Yield Strength, MPa 170 500 14-35 14 35 105 270 550 Various combinations of Ta, Mo, Ni, Nb, W and Kovar to integrate Silicon nitride to Nickel-Base Superalloys www.nasa.gov 8
  9. 9. 10/25/2012 National Aeronautics and Space Administration Si3N4 (NT 154) bonded to Inconel 625 at 1317 K for 30 min EDS data in (e) correspond to the point markers in (b) The reaction zone (point 4) is rich in Ti and Al, but also contains Cu, Ni, Si, and Cr. No discontinuity, cracking or microvoids are noted in the reaction zone www.nasa.gov National Aeronautics and Space Administration EDS Compositional Maps of Silicon Nitride/Silicon Nitride Joints Using Cu-ABA Interlayers Titanium Segregation at the Interface www.nasa.gov 9
  10. 10. 10/25/2012 National Aeronautics and Space Administration TEM Analysis Silicon Nitride/Silicon Nitride Joints Using Cu-ABA (92.75Cu-3Si-2Al-2.25Ti) Interlayers (a) Reaction layer at the Si3N/braze interface and dislocations in braze, (b) titanium silicide formation, and (c) a higher magnification image of region shown in (b). Details of joint microstructure (fine grains < 50 nm) form the reaction layer. b) Electron diffraction patterns of the Si3N4, reaction layer and joint interior (Cu-ABA). M. Singh, R. Asthana, F.M. Varela, J.M. Fernandez, J. Eur. Ceram. Soc. . 31 (2011) 1309-16 www.nasa.gov National Aeronautics and Space Administration Typical Shear Behavior of Joints at Different Temperatures Stress (MPa) 250 RT 200 150 100 Si3N4 JOINT INCONEL JOINT 50 0 0 5 10 15 20 Strain (%) www.nasa.gov 10
  11. 11. 10/25/2012 National Aeronautics and Space Administration Kyocera SN-281 Si3N4 bonded at 1317 K for 5 min using Cu-ABA (92.75Cu-3Si-2Al-2.25Ti) Interlayers EDS data in (d) correspond to the point markers in (b) M. Singh, R. Asthana, J. R. Rico, J.M. Fernandez, Ceramic International, 38, 4, (2012) 2793-2802 • An inhomogeneous reaction layer (2-2.5 µm) comprising of a dark-gray Ti-Si phase, possibly titanium silicide, and a lighter Cu (Si, Ti) phase has developed. • The product phase crystals are oriented perpendicular to the interface (growth direction). • No interfacial excess of Lu; exists in minute quantities in reaction layer and increases toward Si3N4. www.nasa.gov National Aeronautics and Space Administration Kyocera SN-281 Si3N4 bonded at 1317 K for 30 min EDS data in (d) correspond to the point markers in ( C) M. Singh, R. Asthana, J. R. Rico, J.M. Fernandez, Ceramic International, 38, 4, (2012) 2793-2802 • No increase in reaction layer thickness for 30 min. (faster kinetics in the early stages of reaction). • Morphologically a more homogeneous, compact, and featureless reaction layer (possible coalescence of coarsened silicide crystals). www.nasa.gov 11
  12. 12. 10/25/2012 National Aeronautics and Space Administration Kyocera SN-281 bonded at 1317K for 30 min. (5 µm thick Cu foil inserts: Si3N4/Cu/Cu-ABA/Cu/Si3N4) EDS data in (d) correspond to the point markers in (c) • Sound joint with a compact and morphologically homogeneous reaction layer (~1-2 µm thick). • Ti and Si enrichments at the interface (possible formation of a titanium silicide compound layer). www.nasa.gov National Aeronautics and Space Administration Si3N4/W/Mo/Inconel 625 (Cu-ABA, brazed at 1044C, 30 min.) Ato m % E lem en t Microstructure of Silicon Nitride/Inconel 625 Multilayer Joints 060708-G.SN/Cu-ABA interface 100 90 80 70 60 50 40 30 20 10 0 Interaction zone Al Si Ti Cr Co Ni Cu Mo W 0 5 Cu-ABA side 10 15 Silicon nitride side 20 25 30 35 EDS Point Marker 120 062008-7.SN/Cu-ABA Interface Si3N4/Ni/W/Ni/Inconel 625 (with Cu-ABA on SN side and MBF on Inconel side) (brazed at 1044C, 30 min.) Ato m % E lem en t 100 Al Si Ti Cr Co Ni Cu Mo W 80 Silicon nitride side 60 40 Braze side 20 0 0 5 10 15 20 25 30 35 40 45 EDS Point Marker www.nasa.gov 12
  13. 13. 10/25/2012 National Aeronautics and Space Administration Typical Shear Behavior of Multilayer Joints at Different Temperatures • Si3N4/W/Mo/Si3N4 joint strength (142 MPa) is comparable to Si3N4/Si3N4 strength (141 MP ) t th MPa) • Si3N4/W/Mo/Inconel joint strength (54 MPa) is greater than strength (15 MPa) of Si3N4/Inconel www.nasa.gov National Aeronautics and Space Administration Integration Technologies for Improved Efficiency and Low Emissions • MEMS-LDI Fuel Injector MEMS- www.nasa.gov 13
  14. 14. 10/25/2012 National Aeronautics and Space Administration Integration Technologies for MEMS-LDI Fuel Injector Objective: Develop Technology for a SiC Smart Integrated Multi-Point Lean Direct Injector (SiC SIMP-LDI) - Operability at all engine operating conditions - Reduce NOx emissions by 90% over 1996 ICAO standard - Allow for integration of high frequency fuel actuators and sensors Possible Injector Approaches 1. Lean Pre-Mixed Pre-Evaporated (LPP) Advantages - Produces the most uniform temperature distribution and lowest possible NOx emissions Disadvantages - Cannot be used in high pressure ratio aircraft due to auto-ignition and flashback 2. Lean Direct Injector (LDI) Advantages - Does not have the problems of LPP (auto-ignition and flashback) - Provides extremely rapid mixing of the fuel and air before combustion occurs www.nasa.gov National Aeronautics and Space Administration Lean Direct Injector Fabricated by Bonding of SiC Laminates SiC laminates can be used to create intricate and interlaced passages to speed up fuel-air mixing to allow lean-burning, ultra-low emissions Key Enabling Technologies: • Bonding of SiC to SiC • Brazing of SiC to Metallic (Kovar) Fuel Tubes Benefits of Laminated Plates - Passages of any shape can be created to allow for multiple fuel circuits - Provides thermal protection of the fuel to prevent choking - Low cost fabrication of modules with complicated internal geometries through chemical etching www.nasa.gov 14
  15. 15. 10/25/2012 National Aeronautics and Space Administration Leak Test of SiC Laminates Joined with Silicate Glass Combustion air channels Fuel holes Leaks at the edge between joined laminates Air should only flow through the fuel holes Undesired leaks i U d i d l k in the combustion air channels Plugged fuel hole www.nasa.gov National Aeronautics and Space Administration Diffusion Bonding of CVD-SiC Using PVD Ti Interlayer 20 Micron Ti Interlayer 10 Micron Ti Interlayer Microcracking is still present due to the presence of Ti5Si3CX. No microcracking or phase of Ti5Si3CX is present. Naka et al suggest that this is an intermediate phase. Thin interlayers of pure Ti downselected as the preferred interlayer. A B Phase C Phases in bond with the 20 µ Ti Interlayer – Atomic Ratios Phase Ti Si C Phase A 56.426 17.792 25.757 Phase B 35.794 62.621 1.570 Phase C 58.767 33.891 7.140 Phases in bond with the 10 µ Ti Interlayer – Atomic Ratios Phase Ti Si C SiC 0.011 54.096 45.890 Phase A 56.621 18.690 24.686 Phase B 35.752 61.217 3.028 www.nasa.gov 15
  16. 16. 10/25/2012 National Aeronautics and Space Administration Diffusion Bonding with 20 µm Ti Foil at 1200ºC 4 hr hold 1 1 hr hold hr hold Si C 2 2 hr hold hr hold Si C Si C Si C SiC SiC A B B B C C A A C Si Phase A 54 13 Phase B 57 1 Phase C 44 23 In atomic percent C Si Phase A 55 13 Phase B 58 7 Phase C 47 22 In atomic percent Ti 33 42 33 Ti 32 35 31 C Si Phase A 53 14 Phase B 42 25 In atomic percent Ti 33 33 www.nasa.gov Microcracking is lessened as titanium carbide at the core is reacted away. National Aeronautics and Space Administration TEM Analysis of Diffusion Bonds Processed for 2 Hr 10 μm PVD Ti interlayer 18 21 6 7 15 29 13 SiC substrate 16 20 30 12 1 8 4 10 9 11 9 20 SiC substrate 8 17 26 5 12 25 16 3 24 1μm 23 Ti3SiC2 Ti5Si3Cx TiSi2 TiC unknown 14 30 21 1 Ti3SiC2 Ti5Si3Cx TiSi2 TiC unknown 7 6 27 28 22 5 20 21 26 1μm 20 μm Ti foil interlayer 22 6 18 19 13 Ti3SiC2 Ti5Si3Cx TiSi2 12 22 19 15 17 13 9 17 18 1 2 7 15 21 1μm 7 11 4 Ti3SiC2 Ti5Si3Cx TiSi2 9 10 μm Ti foil interlayer 16 2 33 34 2 6 24 27 32 17 3 26 27 28 14 16 31 8 24 23 29 26 19 10 18 5 SiC substrate 20 25 23 35 19 3 14 1 4 28 22 8 25 10 11 5 20 μm PVD Ti interlayer 15 25 13 14 3 3 4 2 31 23 11 10 12 24 29 1 μm www.nasa.gov 16
  17. 17. 10/25/2012 National Aeronautics and Space Administration Fractions of Phases in Each Sample TiSi2 10 μm Ti5Si3Cx Ti3SiC2 Ti3SiC2 Sample 1 10 μm PVD Ti interlayer PVD Ti 10 μm Ti foil interlayer TiSi2 Sample 2 20 μm PVD Ti interlayer 20 μm Ti foil interlayer unknown 10 μm unknown 20 μm TiSi2 Ti5Si3Cx TiC TiC TiSi2 Ti5Si3Cx Ti3SiC2 Ti5Si3Cx Ti foil Sample 3 20 μm Ti3SiC2 Sample 4 www.nasa.gov National Aeronautics and Space Administration Fractions of Phases in Each Sample TiSi2 10 μm Ti5Si3Cx Ti3SiC2 Ti3SiC2 Sample 1 10 μm PVD Ti interlayer PVD Ti Sample 2 20 μm PVD Ti interlayer A2 B2 A1 10 μm Ti foil interlayer μ y B1 unknown TiSi2 20 μm TiSi2 Ti5Si3Cx 20 μm Ti foil interlayer μ y unknown 10 μm TiC TiC C2 20 μm TiSi2 Ti3SiC2 Ti Si C In the 5 3 x 1, the fraction of Ti3SiC2 was highest andTi5Si3Cx sample Ti3SiC2 that the reaction maythe fraction of Ti5Si3Cx was lowest or zero. This suggests have been complete. On the other hand, in the sample 2, less Ti3SiC2 and more Ti5Si3Cx formed. Additionally, the intermediate Ti5Si3Cx phase has anisotropic thermal expansion. Sample 3microcracking was observed in theSample4 Sample2.4 www.nasa.gov Therefore, sample Ti foil 17
  18. 18. 10/25/2012 National Aeronautics and Space Administration Fractions of Phases in Each Sample TiSi2 In the sample 3, microcracks were scarcely observed. This may relate to the presence of a phase with TiSi2 Ti5Si3C 20 μm relatively high Si xcontent phase. 10 μm Ti5Si3Cx Moreover, if the unknown phase detected in the sample 4 has content similar to that from SEM which had lower Si content, this may also cause microcracks in sample 4. Ti3SiC2 Ti3SiC2 Si C Sample 1 A 10 μm PVD Ti interlayer B C PVD Ti A Sample 2 B 20 μm PVD Ti interlayer C SiC μ y 10 μm Ti foil interlayer TiSi2 μ y 20 μm Ti foil interlayer unknown 10 μm unknown TiC TiC TiSi2 Ti5Si3Cx Ti3SiC2 Ti5Si3Cx Ti foil Sample 3 20 μm Ti3SiC2 Sample 4 www.nasa.gov National Aeronautics and Space Administration Non-Destructive Evaluation (NDE) Using Ultrasonic Immersion Shows Very Good Bonding of 1” Discs Less Polished SiC Highly Polished SiC Discs Before Bonding g 0.65” Diameter PVD Ti Coating Ultrasonic C-scan Image of Bonded Discs Clay on backside of sample to verify that ultrasound reached backwall Ti bonded region Ultrasonic C-scan Image of Bonded Discs Clay on backside of sample to verify that ultrasound reached backwall www.nasa.gov 18
  19. 19. 10/25/2012 National Aeronautics and Space Administration High Strength of Bonds Greatly Exceeds the Application Requirements 1” x 1” Bonded Substrates 1” Diameter Discs with a 0.65” Diameter Bond Area 15 Stress (MPa) 12 Unpolished SiC p Polished SiC 9 6 3 0 0 0.25 0.5 0.75 Strain (mm) Pull test tensile strengths: ( ) > 23.6 MPa (3.4 ksi)* > 28.4 MPa (4.1 ksi)* * failure in the adhesive to the test fixture Pull test tensile strengths: 13.4 MPa (1.9 ksi) 15.0 MPa (2.2 ksi) Slightly higher strength from the highly polished SiC suggests that a smoother surface contributes to stronger bonds or less flawed SiC. Failures are primarily in the SiC substrate rather than in the bond area. The injector application requires a strength of about 3.45-6.89 MPa (0.5 - 1.0 ksi). www.nasa.gov National Aeronautics and Space Administration Demonstration of Diffusion Bonding of 4” Diameter CVD SiC Discs Joined 4” diameter SiC discs. S ti d for i Sectioned f microscopy and to demonstrate leak free at bonded and machined edges. C Si Phase 1 57 9 Phase 2 34 28 Phase 3 50 14 In atomic percent Ti 34 38 36 www.nasa.gov 19
  20. 20. 10/25/2012 National Aeronautics and Space Administration Detail of the Thickest Injector Substrate (~0.635 cm thick) Ai H l Air Hole Passage Fuel Hole and Channel www.nasa.gov National Aeronautics and Space Administration Details of Three Part 10 cm (4”) Diameter SiC Injector Fuel Tube Stacking Sequence Top to Bottom Top Surfaces (Facing the Flow Direction) Small Fuel Holes Fuel Swirler Detail PVD Ti Coated Detail Next Slid Slide Bottom Surfaces (Facing Opposite to the Flow Direction) Large Air Holes Holes for Fuel Tube Integration 40 Stacking Sequencewww.nasa.gov Bottom to Top 20
  21. 21. 10/25/2012 National Aeronautics and Space Administration www.nasa.gov National Aeronautics and Space Administration Ceramic Integration Technologies for Alternative Energy Systems Alt ti E S t - Solid Oxide Fuel Cells www.nasa.gov 21
  22. 22. 10/25/2012 National Aeronautics and Space Administration Integration of YSZ/Steel for SOFC Applications • Gold-ABA and Gold Gold-ABA-V YSZ Steel 3 µm Gold-ABA-V Gold-ABA-V before oxidation Steel Gold ABA-V 850C, 200 min. YSZ 10 µm Gold-ABA-V 1 5 µm EDS of Gold-ABA before and after oxidation 220 YSZ/Gold-ABA/Steel YSZ/Gold-ABA V/Steel 200 Approx. braze region Stainless steel YSZ 180 KHN ABA-V exhibit linear oxidation kinetics at 850 C. Gold-ABA-V shows faster oxidation kinetics than Gold-ABA. • Ti in Gold-ABA and V in Gold-ABA V caused discoloration (darkening) of YSZ. • The darkening is caused by Ti and V that act as oxygen getters and form oxygendeficient YSZ. No reaction layers formed at joint. • The oxygen-deficient YSZ is better wet by gold than stoichiometric YSZ. 160 140 120 100 0 100 200 300 400 500 600 700 Dista nce , m icrom e ter M. Singh, T. Shpargel, R. Asthana, Int. J. Appl. Ceram. Tech. 4(2), 2007, 119-133. www.nasa.gov National Aeronautics and Space Administration Transmission Electron Microscopy of As-Received and Oxidized Foils of 96.4Au-3Ni-0.6Ti Alloy As Received Oxidized K. Lin, M. Singh, and R. Asthana, Materials Characterization 63 (2012) 105-111. www.nasa.gov 22
  23. 23. 10/25/2012 National Aeronautics and Space Administration Transmission Electron Microscopy of As-Received and Oxidized Foils of 97.5Au-0.75Ni-1.75V Alloy As Received Oxidized K. Lin, M. Singh, and R. Asthana, Materials Characterization 63 (2012) 105-111 www.nasa.gov National Aeronautics and Space Administration Transmission Electron Microscopy of Interfaces in YSZ/Au-Ni-Ti/Steel System K. Lin, M. Singh, and R. Asthana, Unpublished work (2012) www.nasa.gov 23
  24. 24. 10/25/2012 National Aeronautics and Space Administration Integration of YSZ/Steel for SOFC Applications • Structural changes accompany g p y oxidation which is fastest for Palco, slowest for Palni, and intermediate for Palcusil-10 and Palcusil-15. 113 Palco 111 109 W eight, % • Pd-base brazes (Palco and Palni) and Ag-base brazes (Palcusil-10 and Palcusil-15) were characterized for oxidation at 750ºC. Palcusil-10 107 Palcusil-15 105 103 Palni 101 99 YSZ 97 95 0 2000 4000 8000 Time, s • All brazes were effective in joining yttria stabilized zirconia (YSZ) to stainless steel for solid oxide fuel cell (SOFC). 10000 12000 2 3 14000 Ag-rich Cu-rich 2 µm • Dissolution of YSZ and steel in braze, and braze constituents in YSZ and steel led to diffusion and metallurgically sound joints. • Knoop hardness (HK) profiles are similar for all brazes, and exhibit a sharp discontinuity at the YSZ/braze interface. 6000 Palcusil-15 Ag-rich Steel Palcusil-15 Cu-rich steel 2 µm M. Singh, T. Shpargel, R. Asthana, Mater. Sci. Eng. A 485 (2008) 695-702 www.nasa.gov National Aeronautics and Space Administration Transmission Electron Microscopy of Interfaces in YSZ/Ag-Cu-Pd/Steel System K. Lin, M. Singh, and R. Asthana, Ceramics International, 38 (2012) 1991–1998. www.nasa.gov 24
  25. 25. 10/25/2012 National Aeronautics and Space Administration Transmission Electron Microscopy of Interfaces in YSZ/Ag-Cu-Pd/Steel System K. Lin, M. Singh, and R. Asthana, Ceramics International, 38 (2012) 1991–1998. www.nasa.gov National Aeronautics and Space Administration Integration of YSZ/Steel for SOFC Applications • Active braze alloys, Cu-ABA, Ticuni and Ticusil, were characterized for oxidation at 750 850 C. 750-850ºC. Ticuni steel 3µm Stainless Steel Steel YSZ Ticuni YSZ • Oxidation is fastest for Ticusil, slowest for Cu-ABA, and intermediate for Ticuni. Reaction layer 3 300um YSZ 4 Reaction layer • Brazes were used for joining yttria-stabilized-zirconia (YSZ) to stainless steel for Solid Oxide Fuel Cell (SOFC) applications. YSZ/Ticuni/Steel YSZ/Ticusil/Steel 1000 YSZ/Cu-ABA/Steel Joint 800 Stainless steel KHN • Interdiffusion, compositional changes, and reaction layer formation led to high-integrity joints. 2 µm 1200 600 YSZ 400 200 0 0 200 400 600 800 1000 1200 1400 Dista nce , m icrom e te r M. Singh, T. Shpargel, R. Asthana, J. Mater. Sci 43 (2008) 23-32 www.nasa.gov 25
  26. 26. 10/25/2012 National Aeronautics and Space Administration Concluding Remarks • Ceramic integration technologies are critically needed for the successful development and applications of ceramic components in a wide variety of energy applications. • M j efforts are needed in developing joint design Major ff t d di d l i j i td i methodologies, understanding the size effects, and thermomechanical performance of integrated systems in service environments. • Development of life prediction models for integrated components is needed for their successful implementation. In addition, global efforts on standardization of integrated ceramic testing and standard test method development are also required. www.nasa.gov National Aeronautics and Space Administration Acknowledgements • Prof. Rajiv Asthana, University of Wisconsin-Stout • Mr. Craig E. Smith, Ohio Aerospace Institute • Mr. Michael H. Halbig, NASA Glenn Research Center • Prof. J.M. Fernandez, University of Seville, Spain • Mr. Ron Phillips, ASRC Corp. • Mr. Ray Babuder, Case Western Reserve University • A number of summer students www.nasa.gov 26

×