Superconductivity UK

Dr. Philip Sargent, Diboride Conductors Ltd.

Commercial superconductorsfor motors and generators

Commercial Wire & Tape

• Commercial production:• Niobium alloys (NbTi, Nb3Sn etc)• B2223 / silver tape - 1st Generation HTS

• Pre-commercial:• MgB2

• Industrial laboratory:• YBCO 2nd Generation HTS “coated conductor”

1910 1930 1950 1970 1990

20

40

60

80

100

120

140

160

Tran

sitio

n te

mpe

ratu

re (K

)

Superconductors

Hg Pb NbNbC NbN

V3Si

Nb3Sn Nb3Ge

Leigh JarvisLeigh Jarvis

Liquid Nitrogen (77K)

Liquid Methane LNG (112K)

(La, Ba) Cu)(La, Ba) Cu)

HgBa2Ca2Cu3O9(under pressure)

HgBa2Ca2Cu3O9

TlBaCaCuO

B2223 - Bi2Sr2Ca2Cu3O

YBCO - YBa2Cu3O7

MgB2

Tl, Hg…(138K)

More superconductors

1980- (TMTSF)2PF6

YPd2B2C HoMo6S8 (Chevrel) ErRh4B4 CeRu2 heavy fermion1991 - K3C60 Fullerene1994 - Sr2RuO4 2001 – MgB2

2001- C nanotubes2002 - PuCoGa5 (18K)

Nature 6 Mar.2003 - Na0.35CoO2•1.3H2O

HTS –complex copper oxides

                                

                               B2223 - Bi2Sr2Ca2Cu3O YBCO - YBa2Cu3O7

HTS –perovskite ceramics

CuOBa

Y

Ba

YBCO - YBa2Cu3O7B2223 - Bi2Sr2Ca2Cu3O

Engineering Implications

• Requires near single-crystal microstructure by complex processing,

• Oxide requires furnace treatment in controlled oxygen atmosphere, in silver,

• Highly anisotropic resulting tape:• Along and across tape,• Sensitive to magnetic field direction!

B2223 multifilamentary tape -1

           

                             

              

                            

                         

                   

• Fill silver tube with precursor powders.

• Reduce by extrusion, swaging, drawing and rolling to a mono-filament aligned-crystal wire.

• Restack bundle in another silver tube.

B2223 multifilamentary tape -2

• Draw multifilament• Draw to align crystals• Roll to tape • Furnace heat treat

AMSC & Sumitomo

• AMSC & Sumitomo have a reciprocal licensing agreement

American Superconductor 55 filament (B2223) tape

Sumitomo (B2223) tape

AMSC B2223 Manufacturing Plant

Larger billets, Process automation, Longer Larger billets, Process automation, Longer strands, Multi-dies, Faster line-speed, strands, Multi-dies, Faster line-speed, Combination of process stepsCombination of process steps

Began volume production in early 2003Began volume production in early 2003 Full capacity could be 20,000 km/year, now Full capacity could be 20,000 km/year, now

900 km/year900 km/year

                     

> 150 m lengths

170 A also demonstrated in short lengths170 A also demonstrated in short lengths

0

2

4

6

8

10

12

14

16

18

20

22

24

26

28

30

32

100 103 105 108 110 113 115 118 120 123 125 128 130 133 135 138 140 143 145 148 150

End to End Critical Current, Amps

Freq

uenc

y

Manufacturing Campaign for Detroit EdisonManufacturing Campaign for Customer X (2002)

(B2223) Critical Currents 2001-02 Manufacturing variability

Measured at AMSC & UWUniversity of Wisconsin

12

13

14

15

16

17

18

19

20

21

1994 1995 1996 1997 1998 1999 2000 2001 2002

Jc (A

/cm

2, 7

7 K

, 0.1

T, //

c)

Measured at AMSC andMeasured at AMSC andUniversity of WisconsinUniversity of Wisconsin

Jc of 19.8kA/cm2 (77K, 0.1T, //c):Jc of 19.8kA/cm2 (77K, 0.1T, //c): a new level of performance for wire a new level of performance for wire with production architecturewith production architecture

Measurement in 0.1 T field avoids self-field current suppressionMeasurement in 0.1 T field avoids self-field current suppression

B2223 Wire Improvement

Current Distributions in B2223

180 kA/cm180 kA/cm22 Regions Observed in AMSC Monocore Tapes Regions Observed in AMSC Monocore Tapes Headroom for Further Current Density ProgressHeadroom for Further Current Density Progress

(U. Wisconsin/AMSC)(U. Wisconsin/AMSC)

AMSC B2223 Plant History

• Development started in summer 1988Development started in summer 1988• 10 years (1998): 10 years (1998):

• AMSC produces 20 km in 200 m lengths with AMSC produces 20 km in 200 m lengths with an average current of 90 A at 77 Kan average current of 90 A at 77 K

• 14 years: 900km/y plant fully operational14 years: 900km/y plant fully operational• 15 years: 900km/y plant & B2223 IPR 15 years: 900km/y plant & B2223 IPR

value of $22m written off !value of $22m written off !

• How much does it cost to buy the wire to carry 1000 Amps a distance of 1m?

• Copper: 6 $/kA.m – 22 $/kA.m depending on current density (400 – 100 A/cm2)

• Superconductors typically quoted at Jc and at 77K and either zero magnetic field or “self field”.

• Cryogenic OFHC copper can be 0.06 $/kA.m.• NbTi is approx. 0.9 $/kA.m in liquid helium.

Price/Performance $/kA.m

Reduced Manufacturing Costs ($/m) Reduced Manufacturing Costs ($/m) andand Increased Wire Increased Wire Performance (current carrying capacity)Performance (current carrying capacity)

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

$/kA.m

0

200

400

600

800

1000

1200Pr

ice/

Perf

orm

ance

Rat

io, $

/kA

-m

World’s First HTS Wire Manufacturing Plant

Opened By AMSC

Price/Performance $/kA.m

200 $/kA.m

B2223 & Commercial Products• At $50/kAm (77K) price/performance ratio

significant markets would be enabled (it was thought in ~1999):− Utility Generators (>100MVA)Utility Generators (>100MVA)− Ship Propulsion Motors and Generators (>5MW)Ship Propulsion Motors and Generators (>5MW)− Wind Turbine Generators (>4MW)Wind Turbine Generators (>4MW)− Urban T&D Power CablesUrban T&D Power Cables− Industrial Magnetic ProcessingIndustrial Magnetic Processing

• Significant worldwide industry in B2223American Superconductor, Innova, Nordic Superconductor, Sumitomo American Superconductor, Innova, Nordic Superconductor, Sumitomo Electric, Vacuumschmelze, TrithorElectric, Vacuumschmelze, Trithor

Bought and shut down by AMSC in 2002

Magnetic Field

• High magnetic field reduces current carrying capacity

• Lower temperatures enhance current carrying capacity

• B2223 must operate 20K – 40K for motors which have fields ~ 2T

• B2223 at 27K carries twice the current, so $/kA.m reduces to 100 $/kA.m.

Saturation in Fe-3%Si at 1.6T

Flux

Den

sity

, B (T

)1.6

Critical CurrentDensity, A/mm²

10

100

1,000

10,000

100,000

0 5 10 15 20 25 30Applied Field, T

Nb3AlNb-Ti

2212

2223

At 4.2 K UnlessOtherwise Stated

2212

YBCO

MgB2Film

YBCO75 K H||a-b

YBCO75 K H||c

1.8 K Nb-Ti-Ta

PbSnMo6S8

1.8 K Nb-Ti

Nb3Sn Tape from (Nb,Ta)6Sn5

Nb-TiHT

Nb-TiAPC

Nb3SnBronze Low Field

Nb3SnBronze High Field

Nb3SnHigh Sn

Critical CurrentDensity, A/mm²

10

100

1,000

10,000

100,000

0 5 10 15 20 25 30Applied Field, T

Nb3AlNb-Ti

2212

2223

At 4.2 K UnlessOtherwise Stated

2212

YBCO

MgB2Film

YBCO75 K H||a-b

YBCO75 K H||c

1.8 K Nb-Ti-Ta

PbSnMo6S8

1.8 K Nb-Ti

Nb3Sn Tape from (Nb,Ta)6Sn5

Nb-TiHT

Nb-TiAPC

Nb3SnBronze Low Field

Nb3SnBronze High Field

Nb3SnHigh Sn

YBCO75 K H||a-b

YBCO75 K H||c

1.8 K Nb-Ti-Ta

PbSnMo6S8PbSnMo6S8

1.8 K Nb-Ti

Nb3Sn Tape from (Nb,Ta)6Sn5

Nb-TiHT

Nb-TiAPC

Nb3SnBronze Low Field

Nb3SnBronze High Field

Nb3SnHigh Sn

Copper: up to 400 A/cm2

Peter Lee’s Cosmic Plot (UW/ASC)MA/cm2

10

1

0.1

0.01

0.001

Power Apps30 – 77 K

1.6T

Key issues for power applications• Overall current density JJee of conductor, not just of superconductor

• Performance in field• Multiple filaments for

AC applications• Anisotropy of Jc with

respect to field direction

• Cost!• Conductor itself• Cooling (AC losses)

• Scalability of fabrication

• Mechanical • Strength, bend radius

• Conductor shape• tape or wire• or new motor designs

Diboride & YBCO

• YBCO and similar compounds have had research worth $$billions devoted to their physics and processing.

• MgB2 was discovered in January 2001; physics now entirely understood.

• Both can be made in:• Tape geometry• Massive lumps for new motor designs

Mg

Mg

Mg

Mg

B

B

B

Magnesium Diboride

Magnesium Diboride

~ 400 $/kg

Making Diboride tape

Cu-sheathed tape

transverse cross section

Tube filling with MgB2 reacted powders

Wire drawing and/or rolling

Flat rolling

Long lengths can be now fabricated

irregular cross sectionSimple sintering ~700C

tube filling

PIT Processing routes for the fabrication of MgB2 wires

+B Mg

a)IN-SITU

b)

MgB2 EX-SITU

100m lengths of tapesimple sintering

reaction sintering23% porosity

draw to wire

IN-SITU

EX-SITU

Ball milling under Ar

P. I. T.

Swege

Draw

Flat rolling

in= 5 mm

out= 8 mm

= 3.85 mm

= 2 mm

Tape 4 x 0.38 mm2

P.I.T.

Flat rolling

Final Tape

MgB2

Université de Genève

Powder in Tube

HyperTech CTFF for MgB2

CONTINUOUS TUBE FORMING AND FILLING (CTFF)

Irreversibility field

• Increase magnetic field capability by metallurgy

• Create pinning defects by controlled alloying of MgB2

L. Cowey et al., MgB2 + yttria

10-Meter Long Square MgB2 Wire

Texas Center for Superconductivity and Advanced Materials University of HoustonNASA Commercial Space Center CSAMT

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.4005

10152025303540455055606570

9 T

7 T

strain (%)I c (

A)

Strain Effect on MgB2 long tape 100 h ball milled

Strain gauges

Modified Walters Spiral (WASP)

MgB2 Tape

d=26 cm

Université de Genève

In situ B+Mg with Fe barrier in Monel Sheath

With iron –tough to make multifilament- most likely be cabled ,(twisted) monofilaments for low AC loss conductor, working onOuter sheaths of Monel, Cu/Ni, and Cu to improve stabilization.

Hyper Tech Research

Reasonable properties can be obtained with all Cu wires,Or with with Nb barriers in Cu.

Multifilament wires can be made

Hyper Tech Research

Shows ITER barrel wound with over 1 meter of MgB2 wire, all Cu sheath, 1.00 mm diameter wire. The self field transport current for the coil at 4.2 K was 450 amps, the estimated transport current at 20 K would be 150-180 amps.

Hyper Tech Research

First test of an MgB2 pancake

3.0 3.5 4.0 4.5 5.00

50

100

150

200

250

4.2 KC

ritic

al C

urre

nt [A

]

Magnetic Field [T]

MgB2 pancake BSCCO pancake

MgB2

BSCCO

Critical CurrentDensity, A/mm²

10

100

1,000

10,000

100,000

0 5 10 15 20 25 30Applied Field, T

Nb3AlNb-Ti

2212

2223

At 4.2 K UnlessOtherwise Stated

2212

YBCO

MgB2Film

YBCO75 K H||a-b

YBCO75 K H||c

1.8 K Nb-Ti-Ta

PbSnMo6S8

1.8 K Nb-Ti

Nb3Sn Tape from (Nb,Ta)6Sn5

Nb-TiHT

Nb-TiAPC

Nb3SnBronze Low Field

Nb3SnBronze High Field

Nb3SnHigh Sn

Critical CurrentDensity, A/mm²

10

100

1,000

10,000

100,000

0 5 10 15 20 25 30Applied Field, T

Nb3AlNb-Ti

2212

2223

At 4.2 K UnlessOtherwise Stated

2212

YBCO

MgB2Film

YBCO75 K H||a-b

YBCO75 K H||c

1.8 K Nb-Ti-Ta

PbSnMo6S8

1.8 K Nb-Ti

Nb3Sn Tape from (Nb,Ta)6Sn5

Nb-TiHT

Nb-TiAPC

Nb3SnBronze Low Field

Nb3SnBronze High Field

Nb3SnHigh Sn

YBCO75 K H||a-b

YBCO75 K H||c

1.8 K Nb-Ti-Ta

PbSnMo6S8PbSnMo6S8

1.8 K Nb-Ti

Nb3Sn Tape from (Nb,Ta)6Sn5

Nb-TiHT

Nb-TiAPC

Nb3SnBronze Low Field

Nb3SnBronze High Field

Nb3SnHigh Sn

Peter Lee’s Cosmic Plot (UW/ASC)MA/cm2

10

1

0.1

0.01

0.001

Power Apps30 – 77 K

Genoa25 K

Magnesium Diboride (MgB2 )• Advantages

• No weak-link effects, low anisotropyNo weak-link effects, low anisotropy• Easy to fabricate wires, films: <$10/kA.m potentialEasy to fabricate wires, films: <$10/kA.m potential

• Challenges • TTcc < 40 K (77 K applications like cables, transformers not viable) < 40 K (77 K applications like cables, transformers not viable)• High field applications such as NMR not viableHigh field applications such as NMR not viable

• Possible applications in 20-30K range for modest field environments, e. g., rotating machinery

YBCO Coated Conductor

• Rolled, textured Nickel tape (Ni-W)• Oxide buffer layer, preserves texture• YBCO (or analogue, e.g. HoBCO), preserves texture

• Near “single crystal” 100s of metres longNear “single crystal” 100s of metres long• <$10/kA.m potential<$10/kA.m potential

YBCO Coated Conductor

Sumitomo YBCO-CC

YBCO

                           

                               

Ni tape

Oxide buffer layer deposition

YBCO

                           

                               

YBCOprecursor

                           

                         

YBCO oxygenationand conversion

                          

                               

                             

                              

YBCO

                           

                               

Slitting

                           

                         

                          

                               

                             

                              

                         

                              

YBCO Coated Conductor tape

• Active programs in US, Japan and Europe

• Examples of results in 2001: • 122 A (75 K) over 1 m by LANL122 A (75 K) over 1 m by LANL

− World record for meter lengthWorld record for meter length

• 50 A over 10 m by Fujikura50 A over 10 m by Fujikura− World record for 10 meter lengthWorld record for 10 meter length

• Over 60 m :FujikuraOver 60 m :Fujikura− World’s longest processed tapeWorld’s longest processed tape

Comparative Development

• YBCO CC• Fujikura announces YSZ-IBAD process, early 1991Fujikura announces YSZ-IBAD process, early 1991• Ten years later (2001):Ten years later (2001):

• Fujikura produces Fujikura produces 10 m10 m with 50 A (77 K) with 50 A (77 K)

• B2223• Work started in summer 1988Work started in summer 1988• Ten years later (1998): Ten years later (1998):

• AMSC produces AMSC produces 20 km20 km at minimum 200 m piece length with an at minimum 200 m piece length with an average current of 90 A (engineering current density 11,000 A/cmaverage current of 90 A (engineering current density 11,000 A/cm22 at 77 K)at 77 K)

YBCO CC Technical Issues• Adequate uniformity over length

• Stability to over-currents or cracks

• Adequate current in MOD films

• Mechanical properties – spalling, cracking

• Stability of metal-oxide epitaxial interface

• Deposition rate for ion beam and laser processes

• Thicker than 3 micron YBCO ?

• …but must have that 10 $/kA.m process!

B2223 (1G) to YBCO (2G)

                       

                                        

Reduced Manufacturing Costs ($/m) Reduced Manufacturing Costs ($/m) andand Increased Wire Increased Wire Performance (current carrying capacity)Performance (current carrying capacity)

1995 1996 1997 1998 1999 2000 2001 2002 2003 2004

$/kA.m

0

200

400

600

800

1000

1200Pr

ice/

Perf

orm

ance

Rat

io, $

/kA

-m

World’s First HTS Wire Manufacturing Plant

Opened By AMSC

Price/Performance $/kA.m

200 $/kA.m

AMSC 2G Plant

• 25th Sept. 2003• ORNL award of $2.5m to AMSC to commercialise 2G

process• 1st October 2003

• First tranche of $10m from US DoD and DOE to build 2G plant for YBCO-CC tape over 3 years.

• 3rd October 2003• $44m share issue priced to be used to build 2G plant

• but all committed on pre-commercial processes!

Effort

Per

form

ance

Technology ‘S’ Curves

Effort

Per

form

ance

Copper-Iron

HTS g1

MgB275y 17y

2003

HTS g2

Power Technologies

Conclusions:Superconductors for Motors

• HTS G1:• B2223 tape

• Diboride:• MgB2 wire• MgB2 HIPped bars

• HTS G2:• YBCO CC tape• YBCO cast crystals