Claims
- 1. A method of making a sintered wire of a ceramic copper oxide superconductive material, comprising the steps of:
- packing powders of metal oxides or a mixture of powders of metal oxides and metal carbonates, which, when sintered, form the ceramic copper oxide superconductive material, said oxides and said carbonates each having an oxidation potential (.DELTA.G.degree.) higher than or equal to that of copper, in a metallic cylinder formed from a high-pressure oxidation-resistant material, which high-temperature oxidation-resistant material does not react with said powders of metal oxides and metal carbonates, with the proviso that said high-temperature oxidation-resistant material is not selected from the group consisting of high-temperature oxidation-resistant stainless steel and high-temperature oxidation-resistant nickel alloy;
- drawing said packed cylinder, and sintering said drawn packed cylinder in air to form said wire;
- wherein said cylinder is removed prior to the final step of sintering.
- 2. The method of claim 1, comprising the further step of performing an intermediate heat treatment at a temperature at which the metallic cylinder is annealed.
- 3. The method of claim 2, wherein several such intermediate heat treatments are performed.
- 4. The method of claim 3, wherein said powders are sintered during said intermediate heat treatment.
- 5. The method of claim 1, wherein the drawing step is carried out using die drawing, rolling, swaging and/or extrusion.
- 6. The method of claim 1, comprising the further step of particulating said powders prior to said packing step.
- 7. The method of claim 1, wherein said superconductive material is of perovskite or pseudo-perovskite structure.
- 8. The method of claim 1, wherein said superconductive material is selected from the group consisting of Ba-Y-Cu-O, La-Sr-Cu-O, and Ba-La-Cu-O.
- 9. A method of making a sintered wire of a ceramic copper oxide superconductive material, comprising the steps of:
- packing powders of metal oxides or a mixture of powders of metal oxides and metal carbonates which, when sintered, form the ceramic copper oxide superconductive material, said oxides and said carbonates each having an oxidation potential (.DELTA.G.degree.) higher than or equal to that of copper, in a metallic cylinder formed from a high-temperature oxidation-resistant material, which high-temperature oxidation-resistant material does not react with said powders of metal oxides and metal carbonates, with the proviso that said high-temperature oxidation-resistant material is not selected from the group consisting of high-temperature oxidation-resistant stainless steel and high-temperature oxidation-resistant nickel alloy;
- drawing said packed cylinder; and
- sintering said drawn packed cylinder in air to form said wire,
- wherein said cylinder is removed subsequent to the final step of sintering.
- 10. The method of claim 9, comprising the further step of performing an intermediate heat treatment at a temperature at which the metallic cylinder is annealed.
- 11. The method of claim 10, wherein several such intermediate heat treatments are performed.
- 12. The method of claim 11, wherein said powders are sintered during said intermediate heat treatment.
- 13. The method of claim 9, wherein the drawing step is carried out using die drawing, rolling, swaging and/or extrusion.
- 14. The method of claim 9, comprising the further step of particulating said powders prior to said packing step.
- 15. The method of claim 9, wherein said superconductive material is comprised of pervoskite or pseudo-perovskite structure.
- 16. The method of claim 9, wherein said superconductive material is selected from the group consisting of Ba-Y-Cu-O, La-Sr-Cu-O, and Ba-La-Cu-O.
- 17. A product by the process of any one of claims 1-16.
Priority Claims (1)
Number |
Date |
Country |
Kind |
62-96044 |
Apr 1987 |
JPX |
|
Parent Case Info
This is a division of application Ser. No. 07/438,986, filed Nov. 20, 1989, now U.S. Pat. No. 5,100,865, which is a continuation of U.S. application Ser. No. 180,494, filed Apr. 12, 1988, now abandoned.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4906609 |
Yamauchi et al. |
Mar 1990 |
|
5100865 |
Yamamoto et al. |
Mar 1992 |
|
Non-Patent Literature Citations (2)
Entry |
Yamada et al, "Critical Current Density of Wire Type Y-Ba-Cu Oxide Superconductor," Jpn. J. Appl. Phys. 26(5) May 1987 L865-866. |
Kohno et al, "Critical Temperature and Critical Current density of La-Sr-Cu Oxide Wires," Jpn. J. Appl. Phys. 26(5) May 1987 L759-760. |
Divisions (1)
|
Number |
Date |
Country |
Parent |
438986 |
Nov 1989 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
180494 |
Apr 1988 |
|