Thermomechanical means to improve the critical current density of BSCCO tapes

Patent · Mon Jan 01 00:00:00 EST 2001

OSTI ID:873767

Balachandran, Uthamalingam ^[1]; Poeppel, Roger ^[2]; Haldar, Pradeep ^[3]; Motowidlo, Leszek ^[4]

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1. Hinsdale, IL
2. Glen Ellyn, IL
3. Latham, NY
4. Waterbury, CT

A method of preparing wires or tapes including Bi-2223 superconductor material by providing oxide and carbonate sources of Bi, Sr, Ca, Cu and Pb, milling the material for a time not to exceed about 30 minutes but preferably not greater than 20 minutes to produce a homogeneous mixture. Then heat treating by calcining the milled mixture at a temperature of at least about 830.degree. C. for a time not less than about 12 hours, followed by at least one additional milling for a time not to exceed about 20 minutes and one additional heat treatment, to produce an oxide powder having an average diameter in the 4 to 5 micron range. Then a silver or silver alloy tube is filled with the oxide powder, and shape formed into a rectangular tape. Then alternately thermally treating and mechanically working the tube filled with oxide powder by heating the filled tube to an elevated temperature of about 835.degree. C. to 840.degree. C. and reducing the diameter of the tube, repeating the thermal and mechanical treatment. The filled tube is held at the elevated temperature for a total time in the range of from about 48 hours to about 350 hours to provide Pb.sub.0.4, Bi.sub.1.8 Sr.sub.2.0 Ca.sub.2.2 Cu.sub.3 O.sub.x where x is between 10 and 11.

• Research Organization: Argonne National Laboratory (ANL), Argonne, IL (United States)
• DOE Contract Number: W-31109-ENG-38
• Assignee: University of Chicago (Chicago, IL)
• Patent Number(s): US 6240619
• OSTI ID: 873767
• Country of Publication: United States
• Language: English

Related Subjects

thermomechanical
means
improve
critical
current
density
bscco
tapes
method
preparing
wires
including
bi-2223
superconductor
material
providing
oxide
carbonate
sources
sr
cu
pb
milling
time
exceed
30
minutes
preferably
20
produce
homogeneous
mixture
heat
treating
calcining
milled
temperature
830
degree
12
hours
followed
additional
treatment
powder
average
diameter
micron
range
silver
alloy
tube
filled
shape
formed
rectangular
tape
alternately
thermally
mechanically
heating
elevated
835
840
reducing
repeating
thermal
mechanical
held
total
48
350
provide
10
11
additional heat
current density
elevated temperature
heat treatment
critical current
oxide powder
heat treating
homogeneous mixture
superconductor material
mechanical means
thermally treating
tube filled
average diameter
alloy tube
silver alloy
micron range
filled tube
mechanical treatment
bscco tapes
/29/174/505/