1. Thermomechanical Processing of High T c Superconducting Wire Super BSCCO Family C. Bjelkengren B. Cooper S. Maltas Y. King

2. Super BSCCO Family 2 Project Overview BiSrCaCuO-2223 ceramic encased in a silver tape Supercurrent flows along Cu-O planes

3. Super BSCCO Family 3 Project Overview Texture controls critical current Good Bad Worst

4. Super BSCCO Family 4 As-received BSCCO-2223 Properties ST 0.22 mm 4.14 mm Volume % ~ 60 % BSCCO T c : 110 K B c : 10 -2 T I c : 110 A A cross section ~ 0.9 mm 2 At Ni (l) T

5. Super BSCCO Family 5 Available Thermomechanical Processes Cold Rolling Hot Rolling Uniaxial Deformation Compression Annealing Annealing Directional Grain Growth Hot Isostatic Pressing

6. Super BSCCO Family 6 Available Thermomechanical Processes Cold Rolling Hot Rolling Uniaxial Deformation Compression Annealing Directional Grain Growth Hot Isostatic Pressing

7. Super BSCCO Family 7 Temperature ( o C) Time (min) 700800850900 40 60 80 Pure Annealing

8. Super BSCCO Family 8 Cold Rolling Gained Access to Automated Precision Roller in NucE

9. Super BSCCO Family 9 Fixed  O 2 Partial Pressure: 10 7 Pa  Anneal Temperature: 815 o C Variable  Strain: ∆w / w 0  Anneal Time Cold Rolling

10. Super BSCCO Family 10 Strain (∆w/w o ) Time (min) 0.10.20.30.4 40 60 80 Cold Rolling

11. Super BSCCO Family 11 Compression Annealing Simultaneous heat, strain, and oxidation

12. Super BSCCO Family 12 Fixed  O 2 Partial Pressure: 10 7 Pa  Torque: 10 N·m Variable  Anneal Time  Anneal Temperature Compression Annealing

13. Super BSCCO Family 13 Temperature ( o C) Time (min) 200300500700 10 20 40 Compression Annealing

14. Super BSCCO Family 14 Hot Isostatic Pressing t ~ 40 hours T ~ 400-500 o C P ~ 70 MPa Ag-based solder Annealing to restore O x

15. Super BSCCO Family 15 Hot Isostatic Pressing Temperature Time 40 hours Pressure = 70 MPa 500 C

16. Super BSCCO Family 16 Results so Far! Cold Rolling Hot Rolling Uniaxial Deformation Compression Annealing Annealing Directional Grain Growth Hot Isostatic Pressing

17. Super BSCCO Family 17 Results so Far! Cold Rolling Hot Rolling Uniaxial Deformation Compression Annealing Directional Grain Growth Hot Isostatic Pressing

18. Super BSCCO Family 18 Loss of Superconductivity

19. Super BSCCO Family 19 Improvements in Superconductivity

20. Super BSCCO Family 20 I c After Hot Isostatic Pressing ?

21. Super BSCCO Family 21 Further Assessment Deduce:  Most effective process variables using the variable-squares outlined above Relate:  Improvements in I c to better texture Investigate:  Lotgering Factor  SEM

22. Super BSCCO Family 22 Gantt Chart 54321 Pure Anneal (2 out of 8 done) Cold Rolling (2 out of 8 done) Compression Annealing (1 out of 8 done) Hot Isostatic Pressing Prepare Detailed Processing Recepie