superconductivity uk dr. philip sargent, diboride conductors ltd. commercial superconductors for...
TRANSCRIPT
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
Tra
nsi
tio
n t
emp
erat
ure
(K
)
Superconductors
Hg Pb NbNbCNbC NbNNbN
V3SiV3Si
Nb3SnNb3Sn Nb3GeNb3Ge
Leigh JarvisLeigh Jarvis
Liquid Nitrogen (77K)
Liquid Methane LNG (112K)
(La, Ba) Cu)(La, Ba) Cu)(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
Cu
OBa
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 lengths170 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
Fre
qu
ency
Manufacturing Campaign for Detroit Edison
Manufacturing 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/c
m2,
77
K, 0
.1T
, //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 ($/m) andand Increased Wire Increased Wire Performance (current carrying capacity)Performance (current carrying capacity)
Reduced Manufacturing Costs ($/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
1200P
rice
/Per
form
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
Flu
x D
ensi
ty,
B (
T)
1.6
Critical CurrentDensity, A/mm²
10
100
1,000
10,000
100,000
0 5 10 15 20 25 30
Applied Field, T
Nb3AlNb-Ti
2212
2223
At 4.2 K UnlessOtherwise Stated
2212
YBCO
MgB2
Film
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 30
Applied Field, T
Nb3AlNb-Ti
2212
2223
At 4.2 K UnlessOtherwise Stated
2212
YBCO
MgB2
Film
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 section
Simple 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
urr
en
t [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 30
Applied Field, T
Nb3AlNb-Ti
2212
2223
At 4.2 K UnlessOtherwise Stated
2212
YBCO
MgB2
Film
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 30
Applied Field, T
Nb3AlNb-Ti
2212
2223
At 4.2 K UnlessOtherwise Stated
2212
YBCO
MgB2
Film
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 average current of 90 A (engineering current density 11,000 A/cmA/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 ($/m) andand Increased Wire Increased Wire Performance (current carrying capacity)Performance (current carrying capacity)
Reduced Manufacturing Costs ($/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
1200P
rice
/Per
form
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
Pe
rfo
rman
ce
Technology ‘S’ Curves
Effort
Pe
rfo
rman
ce
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