Method for joining superconductor segments to form a superconducting article

Claim 1

A method for joining a segment of a melt textured anisotropically superconducting 123 superconductor to an adjacent melt textured anisotropically superconducting segment of said 123 superconductor to form a coherent article, said superconductor having: (i) a formula L 1 M 2 Cu 3 O 6+ δ, wherein L is a rare earth metal, M is an alkali earth metal and δ is a number from about 0.7 to about 1.0; (ii) unit cells with an a-axis, a b-axis, a c-axis, an ab plane, and an ac plane; (iii) a peritectic temperature; and (iv) a yield stress; said segment and said adjacent segment having ab planes defined by the ab planes of aligned superconductor unit cells therein, to form a larger dimensioned anisotropically superconducting article, comprising the steps of: a. contacting the segment with the adjacent segment such that the ab plane of the segment is within 5° of parallel alignment to the ab plane of the adjacent segment; b. heating the contacted segments to a relaxation temperature of from about 95° C. to about 160° C. below the peritectic temperature of the superconductor; C. further heating the contacted segments to an accelerated reaction temperature of from about 50° C. to about 90° C. below the peritectic temperature, at a rate not in excess of 180° C. hr -1 ; d. maintaining the contacted segments at the accelerated reaction temperature and under a static pressure of from about 50% to about 90% of the yield stress of the superconductor measured at the accelerated reaction temperature for a sufficient period for reaction to join the segments into a coherent article; and e. cooling the coherent article to ambient temperature at a rate not exceeding 150° C. hr -1 .

Claim 2

A method for joining a segment of a melt textured anisotropically superconducting 123 superconductor to an adjacent melt textured anisotropically superconducting segment of said 123 superconductor to form a coherent article, said superconductor having: (i) a formula L 1 M 2 Cu 3 O 6+ δ, wherein L is a rare earth metal, M is an alkali earth metal and δ is a number from about 0.7 to about 1.0; (ii) unit cells with an a-axis, a b-axis, a c-axis, an ab plane, and an ac plane; (iii) a peritectic temperature; and (iv) a yield stress; said segment and said adjacent segment having ab planes defined by the ab planes of aligned superconductor unit cells therein, to form a larger dimensioned anisotropically superconducting article, comprising the steps of: a. contacting the segment with the adjacent segment such that the ab plane of the segment is within 5° of parallel alignment to the ab plane of the adjacent segment; b. heating the contacted segments to a relaxation temperature of from about 95° C. to about 160° C. below the peritectic temperature of the superconductor; C. further heating the contacted segments to an accelerated reaction temperature of from about 50° C. to about 90° C. below the peritectic temperature, at a rate not in excess of 180° C. hr -1 ; d. maintaining the contacted segments at the accelerated reaction temperature and under a static pressure of from about 50% to about 90% of the yield stress of the superconductor measured at the accelerated reaction temperature for a sufficient period for reaction to join the segments into a coherent article; and e. cooling the coherent article to ambient temperature at a rate not exceeding 150° C. hr -1 .

Claim 15

A method for joining a segment of a melt textured anisotropically superconducting 123 superconductor to an adjacent melt textured anisotropically superconducting segment of said 123 superconductor to form a coherent article, said superconductor having: (i) a formula L 1 M 2 Cu 3 O 6+ δ, wherein L is a rare earth metal, M is an alkali earth metal and δ is a number from about 0.7 to about 1.0; (ii) unit cells with an a-axis, a b-axis, a c-axis, an ab plane, and an ac plane; (iii) a peritectic temperature; and (iv) a yield stress; said segment and said adjacent segment having ab planes defined by the ab planes of aligned superconductor unit cells therein, to form a larger dimensioned anisotropically superconducting article, comprising the steps of: a. contacting the segment with the adjacent segment such that the ab plane of the segment is within 5° of parallel alignment to the ab plane of the adjacent segment; b. heating the contacted segments to a relaxation temperature of from about 850° C. to about 920° C.; C. further heating the contacted segments to an accelerated reaction temperature of from about 925° C. to about 960° C. at a rate not in excess of 180° C. hr -1 ; d. maintaining the contacted segments at the accelerated reaction temperature and under a static pressure of from about 2 to about 20 MPa for a sufficient period for reaction to join the segments into a coherent article; and e. cooling the coherent article to ambient temperature at a rate not exceeding 150° C. hr -1 .

Claim 16

A method for joining a segment of a melt textured anisotropically superconducting 123 superconductor to an adjacent melt textured anisotropically superconducting segment of said 123 superconductor to form a coherent article, said superconductor having: (i) a formula L 1 M 2 Cu 3 O 6+ δ, wherein L is a rare earth metal, M is an alkali earth metal and δ is a number from about 0.7 to about 1.0; (ii) unit cells with an a-axis, a b-axis, a c-axis, an ab plane, and an ac plane; (iii) a peritectic temperature; and (iv) a yield stress; said segment and said adjacent segment having ab planes defined by the ab planes of aligned superconductor unit cells therein, to form a larger dimensioned anisotropically superconducting article, comprising the steps of: a. contacting the segment with the adjacent segment such that the ab plane of the segment is within 5° of parallel alignment to the ab plane of the adjacent segment; b. heating the contacted segments to a relaxation temperature of from about 850° C. to about 920° C.; C. further heating the contacted segments to an accelerated reaction temperature of from about 925° C. to about 960° C. at a rate not in excess of 180° C. hr -1 ; d. maintaining the contacted segments at the accelerated reaction temperature and under a static pressure of from about 2 to about 20 MPa for a sufficient period for reaction to join the segments into a coherent article; and e. cooling the coherent article to ambient temperature at a rate not exceeding 150° C. hr -1 .

Claim 26

A method for joining a segment of a melt textured anisotropically superconducting 123 superconductor to an adjacent melt textured anisotropically superconducting segment of said 123 superconductor to form a superconducting article, said superconductor having: (i) a formula L 1 M 2 Cu 3 O 6+ δ, wherein L is a rare earth metal, M is an alkali earth metal and δ is a number from about 0.7 to about 1.0; (ii) unit cells with an a-axis, a b-axis, a c-axis, an ab plane, and an ac plane; (iii) a peritectic temperature; (iv) a yield stress; and (v) a critical superconductive temperature said segment and said adjacent segment having ab planes defined by the ab planes of aligned superconductor unit cells therein, to form a larger dimensioned anisotropically superconducting article, comprising the steps of: a. contacting the segment with the adjacent segment such that the ab plane of the segment is within 5° of parallel alignment to the ab plane of the adjacent segment and such that said contacting defines a lap joint; b. heating the contacted segments to a relaxation temperature of from about 95° C. to about 160° C. below the peritectic temperature of the superconductor; C. further heating the contacted segments to an accelerated reaction temperature of from about 50° C. to about 90° C. below the peritectic temperature, at a rate not in excess of 180° C. hr -1 ; d. maintaining the contacted segments at the accelerated reaction temperature and under a static pressure comprising a stress substantially perpendicular to said contact surfaces of from about 50% to about 90% of the yield stress of the superconductor measured at the accelerated reaction temperature for a sufficient period for reaction to join the segments into a coherent article; and e. cooling the coherent article to ambient temperature at a rate not exceeding 150° C. hr -1 .

Claim 27

A method for joining a segment of a melt textured anisotropically superconducting 123 superconductor to an adjacent melt textured anisotropically superconducting segment of said 123 superconductor to form a superconducting article, said superconductor having: (i) a formula L 1 M 2 Cu 3 O 6+ δ, wherein L is a rare earth metal, M is an alkali earth metal and δ is a number from about 0.7 to about 1.0; (ii) unit cells with an a-axis, a b-axis, a c-axis, an ab plane, and an ac plane; (iii) a peritectic temperature; (iv) a yield stress; and (v) a critical superconductive temperature said segment and said adjacent segment having ab planes defined by the ab planes of aligned superconductor unit cells therein, to form a larger dimensioned anisotropically superconducting article, comprising the steps of: a. contacting the segment with the adjacent segment such that the ab plane of the segment is within 5° of parallel alignment to the ab plane of the adjacent segment and such that said contacting defines a lap joint; b. heating the contacted segments to a relaxation temperature of from about 95° C. to about 160° C. below the peritectic temperature of the superconductor; C. further heating the contacted segments to an accelerated reaction temperature of from about 50° C. to about 90° C. below the peritectic temperature, at a rate not in excess of 180° C. hr -1 ; d. maintaining the contacted segments at the accelerated reaction temperature and under a static pressure comprising a stress substantially perpendicular to said contact surfaces of from about 50% to about 90% of the yield stress of the superconductor measured at the accelerated reaction temperature for a sufficient period for reaction to join the segments into a coherent article; and e. cooling the coherent article to ambient temperature at a rate not exceeding 150° C. hr -1 .