Claims
- 1. A method of manufacturing a ceramic superconductor article of manufacture by sintering a solid mass comprised of powders of the ceramic superconductor composed of a required stoichiometry to be superconducting, comprising the steps of:
- providing a starting powder of said ceramic superconductor compound consisting essentially of YBa.sub.2 Cu.sub.3 O.sub.x, with x being the amount required to achieve the superconducting phase;
- forming a solid mass from said starting powder with said starting powder consisting essentially of YBa.sub.2 Cu.sub.3 O.sub.x ; and
- sintering said solid mass below the melting point of said compound of said ceramic superconductor, said step of sintering including applying to said solid mass a p(O.sub.2) of about 100 Pa to about 1000 Pa and a sintering temperature for achieving a product ceramic superconductor with a density for said solid mass of at least about 91% to about 95% of theoretical and said ceramic superconductor compound consisting essentially of YBa.sub.2 Cu.sub.3 O.sub.x and having a J.sub.c of at least about 155.ANG./cm.sup.2.
- 2. The method as defined in claim 1 wherein said sintering step is performed under time and temperature conditions for achieving a grain size less than 16 .mu.m average diameter.
- 3. The method as defined in claim 1 wherein the J.sub.c is at least about 300.ANG./cm.sup.2.
- 4. The method as defined in claim 1 wherein said sintering temperature is high enough to enable sintering to occur but without wetting of said ceramic superconductor.
- 5. The method as defined in 4 wherein said sintering temperature is less than about 950.degree. C. and more than about 850.degree. C.
- 6. The method as defined in claim 4 wherein said sintering temperature is below said sintering temperatures at which microcracking occurs in said ceramic superconductor,
- 7. The method as defined in claim 1 wherein said step of preparing a starting powder comprises preparing a slip mixture of the compound of said ceramic superconductor.
- 8. The method as defined in claim 7 further including forging a solid mass body of said ceramic superconductor from said slip mixture.
- 9. The method as defined in claim 1 wherein a grain size of said product ceramic superconductor is from about 0.5 .mu.m to about 15 .mu.m.
- 10. The method as defined in claim 9 wherein the length of said grain size is less than about 15 .mu.m.
- 11. The method as defined in claim 1 wherein a grain size of said product ceramic superconductor consists of a distribution having a peak size of about 3 .mu.m to about 5 .mu.m in width and less than about 10% of the grains having grain width in excess of 8 .mu.m to 10 .mu.m.
- 12. The method as defined in claim 11 wherein the length of said grain size is less than about 25-30 .mu.m.
Parent Case Info
This is a continuation of application(s) Ser. No. 07/947,668 filed on Sep. 18, 1992, now abandoned.
Government Interests
The U.S. Government has certain rights in this invention pursuant to Contract No. W-31-109-Eng-38 of the Department of Energy.
US Referenced Citations (7)
Non-Patent Literature Citations (1)
Entry |
Patent Abstracts of Japan 02-135617, Aug. 10, 1990, vol. 14, No. 371. |
Continuations (1)
|
Number |
Date |
Country |
Parent |
947668 |
Sep 1992 |
|