1. September 27, 2016 PNNL SiC/SiC Test Blanket Module Contributions CH Henager, Jr. GE Youngblood RJ Kurtz Pacific Northwest National Laboratory Richland, WA ITER-TBM Meeting August 10-12, 2005 Idaho Falls, ID

2. September 27, 2016 Large, Geometrically Complex Structures can be Readily Fabricated From SiC Actively Cooled Thrust Chambers Misc. Components Combustor Liners

3. September 27, 2016 Thermal Conductivity – Currently Too High FCI Goal

4. Recent Electrical Conductivity Measurements Composite Disk SiC fibers FCI Goal

5. September 27, 2016 Mechanical Properties n SiC/SiC composites are tough and strong but… â Composite cracks expose fibers. â Fatigue due to thermal pulses could pump PbLi into composite interior. â Thermal gradients allow vapor transport. â Thermal stresses and fatigue require study and understanding.

6. September 27, 2016 Joining and Bonding n Joining is a critical technology for ceramics and composites â Fabricated simple shapes in complex structures â Hermetic face plates for SiC/SiC in critical environments â Dissimilar materials issues in radiation effects and mechanical/chemical compatibility â Many methods for joining that can be adapted for TBM needs Pre-ceramic polymer joints Displacement reaction joining Brazing

7. September 27, 2016 Reactive Joining of SiC Using Ti 3 SiC 2 /SiC Composites Joint between  -SiC using displacement reaction between TiC + Si (tape cast powders) processed in argon at 1200˚C/30 MPa. n Strong bonding occurs due to Ti 3 SiC 2 + SiC forming during reaction. Note interfacial carbides formed during the reaction. n Joints are tough and strong since Ti 3 SiC 2 phase exhibits plasticity under some conditions. n Joints can be tailored using other metal carbides reacting with Si.

8. September 27, 2016 Suggested Contributions to ITER TBM Programs utilizing SiC/SiC n Transverse thermal conductivity measurements â TBM design dependent measurements n Transverse and in-plane electrical conductivity measurements â Design and measure low conductivity materials n Mechanics and environmental interactions â Thermal stress gradients and thermal fatigue â PbLi vapor transport and crack growth effects n Joining and bonding â Sealing porous SiC/SiC with hermetic bond layer (design) â Compatibility (stress, fracture, and environmental) in TBM n Modeling â All aspects of thermal and electrical properties â Radiation effects â TBM cracking, thermal fatigue, crack “pumping” of PbLi