2G HTS Wire Development at SuperPower

Transcription

1 superior performance. powerful technology. WAMHTS-4 Barcelona, Spain 2G HTS Wire Development at SuperPower Drew W. Hazelton February 16, 2017 SuperPower Inc. is a subsidiary of Furukawa Electric Co. Ltd.

2 Acknowledgements I would like to acknowledge the contributions of the all the members of the SuperPower team, in particular. Yifei Zhang (electromechanical characterization) Ryusuke Nakasaki (pinning development) Aarthi Sundaram (30 mm development) Paul Brownsey (IcBT measurements) Gene Carota (MOCVD) Masayasu Kasahara (buffer development) Allan Knoll (post MOCVD) 2

3 2G HTS Tape Production 3

4 2G HTS wire production at SuperPower IBAD-MOCVD based REBCO wire on Hastelloy substrate Cross-sectional image of a Cu-plated wire REBCO formulation: AP (Advanced Pinning) with enhanced in-field performance for B//c, targeting at coil applications such as high-field magnets, SMES, motors/generators CF (Cable Formulation) for cables, transformers, FCL I c (77K, s.f.)/12mm = A, piece length = up to 500m. Variations in width (2-12mm), substrate thickness (30, 50 or 100µm) Ag thickness (1-5µm), Cu thickness (10-115µm), and insulation Bonding conductors : 2x2mm, 2x4mm, 2x12mm (face to face / back to back ) 4

5 2G HTS wire has been produced since 2006 Continuous improvements introduced into processing Substrate Electropolishing MOCVD IBAD Buffer Sputtering

6 Conductor development areas Manufacturing improvements are a current focus area Longer uniform piece lengths Run-to-run repeatability Tightening process windows Improving process hardware Maximizing yield Enhancing understanding of pinning optimization for operating conditions (4K/high field, 20-50K/2-5 T, 65-77K, lower fields) Artificial pinning centers (BZO, others) Process control (temperature, growth rate, precursor delivery, etc.) Maximizing Je Thinner substrates Thicker films 6

7 Ic performance of production enhanced A.P. wire at 77K/s.f 600A 400A 12mmW 200A 0m 100m 200m 300m 400m 500m Magnetic, non-contact measurement High special resolution, high speed, reel-to-reel Monitoring I c at multiple production points after MOCVD Capable of quantitative 2D uniformity inspection 7

8 Ic [A] at 4mm Ic performance of enhanced A.P wire at 77K/s.f 500m /4mmW 1 µv/cm Ic : production A Ic : production B n-value : production A n-value : production B Piece length [m] Transport measurement by every 5m, with 40µm copper. Extend the piece length up to 500m 8

9 Ic [A] at 4mmW Performance of enhanced A.P wire (7.5% Zr) 1000 Production Wire B//c 4mm 1 10 B [T] 77.3K 65K 30K 20K 10K 4.2K Ic = 190.9A at 77K Measured by Tohoku University Enhanced A.P wire shows high in-field performance 9

10 High field IcBT data on 7.5% Zr doped sample M Measured at Tohoku Univ 10

11 IcBT typical data enhanced AP 11

12 2G HTS Tape R&D Pinning Thick film Thinner substrates 12

13 TEM analysis for enhanced Zr doping Zr = 7.5% Zr = 11.5% Zr = 15% Size : 4.4~6.2nm Distance: 20.8~26.8nm Size : 4.4~5.6nm Distance: 16~20.7nm Size : 4.4~5.6nm Distance: 12.8~18.3nm 13

14 Combination of I c (B,4K) measured in resistive and superconducting magnets Below 2T 15% Zr tape has lower I c than 7.5% Zr production line tape I c (B), A % Zr, R&D (M ) 7.5% Zr, production line (M3-1176) Highest J c tape from purchased for 32T project 7.5% Zr, R&D (M ) 7.5% Zr, production line (M ) M N1 M N2 M N3 M N1new M N1 M N2 M N3 M N1new M N4 M N7 M N8 M N3new M N4new M N4 M N5 M N1new M N2new M N1a M N2 SP215 M HF B, T

15 R&D tapes with Zr=15% M A.P. type with 15% M High-mag type with 15% Vertical BZO nano-rods with additional horizontal REOx growths 15

16 Production line 7.5% Zr (M ) Production line 7.5% Zr (M ) ReBCO surface of R&D tapes are free from a-axis grains and CuO grains 7.5% Zr R&D (M ) 15% Zr, R&D (M )

17 Very different lift factors for compared tapes Interpretation: Additional pinning centers are not effective at 77K, I c (4.2K, 15T, BIIc), A % Zr, R&D 0 0 M line SF 7.5% Zr, R&D I c (77K, SF), A 7.5% Zr, production 7.5% Zr, production Run Number Tape Lift Factor M % Zr R&D 8.76 M % Zr, R&D 4.72 M % Zr, Production line % Zr, Production

18 Ic [A] at 4.1K/17T Thick film development progressing R&D M Zr 7.5%, high mag 2.7 mm thick REBCO film 600 Applied Field (T) Ic (A) 4 mmw 500 ~2.6 5 pass mm ~ pass mm ~ pass mm 1~0.6 passmm R&D Production High-mag 7.5% Film thickness [um] All B//c 18

19 I c (A) / N-value Development progress of 30µm substrate 160 SCS4030, Ic SCS3030, Ic SCS2030, Ic SCS4030, n-value SCS3030, n-value SCS2030, n-value SCS4030, 144 A SCS3030, 110A SCS2030, 75 A Tape Length (m) Base performance of 30µm substrates are comparable to 50µm. 19

20 Electropolishing, buffer and MOCVD deposition parameters of 30 mm Hastelloy C276 substrate developed AFM 5 x 5 um scan obtained from 30 um thick electropolished Hastelloy C-276. (a) In-plane texture and (b) (110) pole figure of LMO buffered IBAD MgO template on 30 um substrate. (103) Pole figure of REBCO film with 7.5% Zr deposited on IBAD MgO template on 30 µm substrate. 20

21 Improved Je demonstrated with 30 mm tapes SP-215, 50 um substrate M , 30 um substrate 300 Engineering current density at 4.2 K vs. applied field for 30 um and 50 um ReBCO tapes with 7.5% Zr J e (B, 4.2K), ka/cm B, T Measured at NHMFL 21

22 CORC wires using SuperPower tapes 16 superpower tapes wound helically Copper core: 2.2 mm diameter 2 mm wide tapes with 30 μm substrate 6 mm twist pitch with partially transposed tapes for low AC loss Wire outer diameter: 3 mm Terminal diameter: 6.35 mm Nominal wire I c : > 1,000 A (77 K) Applications High field magnets Accelerator magnets Fusion magnets High power density transmission Robust, Flexible, Compact. High magnetic field critical current density obtainable by increasing wire diameter and decreasing substrate thickness CORC Value desired for accelerator magnets such as CCT dipoles Value desired for high-field research magnets CORC

23 Prototyping of quasi-rutherford style cable structure 8x 30 mm substrate x 2mm wide tapes wrapped around 14 mm x 2 mm core (1 mm radius) without Ic degradation. Thinner substrates and narrower tapes will enable smaller, more flexible core.

24 2G HTS Tape electromechanical characterization 24

25 Studies on mechanical/electromechanical properties Mechanical behaviors under various stress conditions at RT and/or 77K Electromechanical testing for stress (strain) dependence of I c at 77K Electromechanical strength determined by critical stress with 95% I c retention Axial tensile RT or 77K w/ I c Transverse tensile Stud method RT or 77K w/ I c Fixture for mechanical/electromechanical testing Normalized I c vs. axial tensile stress for 25

26 Studies on mechanical/electromechanical properties 90 Peel test, RT Transverse tensile Pin-pull method RT Transverse tensile Anvil method RT or 77K Weibull analysis results anvil test 26

27 Electromechanical property - Ic under tension at 77K 550MPa Enhanced A.P New Process A.P Ic/Ic(0)=0.95 SCS12050 with 40µm copper 27

28 Stress-strain relationship curves of four different SCS4050 wires. The critical strain and irreversible strain as well as the corresponding critical stress and irreversible stress illustrate the dependence and independence of these properties on the Cu stabilizer thickness. 28

29 Summary Strong focus on processing to improve uniformity, repeatability, piece lengths and yield. Maximize current capacity while developing next generation equipment When is the time to pull the trigger? Enhance performance parameters for developing operating spaces Thinner substrates Thicker films Optimized pinning Continue to improve mechanical properties Delamination mitigation Ic (e) 29

30 END Thank you for your attention superior performance. powerful technology. SuperPower Inc. 450 Duane Ave. Schenectady, NY USA Tel: (518) Fax: (518)