Process for the production of an elongate body consisting of longitudinally aligned acicular crystals of a superconducting material
AssigneeAsea Brown Boveri AG
InventorGundolf Meyer
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Abstract
Process for the production of an elongate body of longitudinally aligned acicular crystals (3) of the superconducting substance REBa.sub.2 Cu.sub.3 O.sub.6.5+y, with RE=rare earth metal, 0<y<1, in which fine-grained powder (1) with a particle diameter of 0.1-5 .mu.m is sintered for 1-100 h at a temperature of 600.degree.-850.degree. C. with application of a pressure of 100-5,000 bar. For the production of a filament conductor, the powder is filled into a small Ag tube (4), drawn, and pressure sintered at 800.degree. C./10 h under 2,000 bar.
Claims11
A process for the production of an elongate body of a high temperature superconductor consisting of longitudinally aligned acicular crystals of a superconducting ceramic material based on REBa.sub.2 Cu.sub.3 O.sub.6.5+y, with RE=a rare earth metal and 0<y<1, comprising the steps of
- preparing a homogeneous, non-superconducting precursor in powder form with an average particle diameter of 0.5-5 .mu.m;
- said precursor containing the elements RE, Ba and Cu in a stoichiometric ratio of RE:Ba:Cu=1:2:3;
- forming from said precursor powder said elongate body;
- applying to said formed elongate body a pressure of 500-2,000 bar;
- and
- sintering said formed elongate body under said applied pressure for 5-20 h at a temperature of 600.degree.-850.degree. C.
The method of claim 11, wherein said superconductor wire has a critical current density of at least 1,100 A/cm.sup.2.
A process for the production of a superconductor wire of a high temperature superconductor consisting of longitudinally aligned acicular crystals of a superconducting ceramic material based on REBa.sub.2 Cu.sub.3 O.sub.6.5+y, with RE=a rare earth metal and 0<y<1, comprising the steps of
- preparing a homogeneous, non-superconducting precursor powder of REBa.sub.2 Cu.sub.3 O.sub.6.5+y with an average particle diameter of 2 .mu.m by mixing powders of an oxide of RE, BaO and CuO in a stoichiometric ratio of RE:Ba:Cu=1:2:3, and repeatedly sintering and milling said mixture;
- filling said non-superconducting precursor powder into a small silver tube, to form a filled silver tube;
- drawing said filled silver tube down to a filament conductor;
- and
- sintering said filled silver tube for 10 h at a temperature of 800.degree. C. and at an external pressure of 2,000 bar to form said superconductor wire.
Dependencies are inferred from the claim text.