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CN-122000129-A - Method for preparing superconducting bulk by top seed crystal fusion texture growth and superconducting bulk

CN122000129ACN 122000129 ACN122000129 ACN 122000129ACN-122000129-A

Abstract

The application provides a method for preparing a superconducting block by melting texture growth of a top seed crystal and the superconducting block, and relates to the technical field of superconducting materials, comprising the steps of adopting RE 2 O 3 、BaCuO 2 and CuO to mix at a molar ratio of 1:x:1; x is 2.3-3.0, preparing a blank, heating the blank to 900-910 ℃ at the speed of 80-110 ℃ per hour, preserving the temperature for 8-10 hours, then carrying out heat treatment on superconducting blocks (YBCO, gdBCO, smBCO and the like) correspondingly prepared by rare earth elements according to corresponding temperature control procedures, and finally cooling to room temperature along with furnace temperature to obtain REBCO superconducting blocks. Greatly improves the preparation efficiency, reduces the cost and optimizes the superconducting performance.

Inventors

  • LI QIANG
  • DENG ZIGANG
  • LI TINGTING
  • Xiong Junjia

Assignees

  • 西南交通大学

Dates

Publication Date
20260508
Application Date
20260119

Claims (10)

  1. 1. A method for preparing a superconducting bulk material by top seed crystal melt textured growth, comprising: Mixing RE 2 O 3 、BaCuO 2 and CuO, and pressing to obtain a precursor block, wherein RE is a rare earth element, the molar ratio of RE 2 O 3 ：BaCuO 2 to CuO is 1:x:1, and x is 2.3-3.0; Pressing Yb 2 O 3 or Y 2 O 3 powder to obtain a support gasket; Sequentially superposing an Al 2 O 3 plate, an MgO single crystal, a support gasket, a precursor block and an NdBCO seed crystal doped with MgO from bottom to top, and assembling to obtain a blank; heating the blank body to 900-910 ℃ at the speed of 80-110 ℃ per hour, preserving the temperature for 8-10 hours, then performing heat treatment by a preset temperature control program corresponding to rare earth elements for preparing superconducting blocks, and finally cooling to room temperature along with furnace temperature to obtain REBCO superconducting blocks; And performing oxygen permeation treatment on the REBCO superconducting bulk material to obtain the superconducting bulk material with single domain texture.
  2. 2. The method of preparing a superconducting bulk material by top seed melt textured growth of claim 1, comprising: Mixing barium carbonate and copper oxide according to a molar ratio of 1:1, and ball milling for 4-5 hours to obtain mixed powder; And calcining the mixed powder, then re-ball milling, and repeating the calcining and ball milling for at least three times to obtain BaCuO 2 powder.
  3. 3. The method of preparing a superconducting bulk material by top-seeded melt textured growth of claim 2, wherein the calcination conditions are calcination at 900 ℃ to 920 ℃ for 24 to 28 hours.
  4. 4. The method of preparing superconducting bulk material by top-seeded melt textured growth of claim 1, wherein the oxygen permeation treatment comprises cooling the REBCO superconducting bulk material from 430 ℃ to 350 ℃ in a circulating oxygen environment, and annealing for 195-205 hours.
  5. 5. The method of preparing a superconducting bulk material by top-seeded melt textured growth of claim 1, wherein the RE 2 O 3 is a rare earth oxide, including any one of Y 2 O 3 、Gd 2 O 3 、Sm 2 O 3 .
  6. 6. The method of preparing superconducting bulk material by top-seeded melt textured growth according to claim 1, wherein when the RE is Gd, the preset temperature control program is to raise the temperature to 1050-1058 ℃ at 60-70 ℃ per hour, keep the temperature for 1.5-2.5 hours, then lower the temperature to 1030-1035 ℃ at 18-28 ℃ per hour, and then lower the temperature to 1005-1018 ℃ at 0.2-0.4 ℃ per hour.
  7. 7. The method for preparing superconducting bulk material by top seed crystal melt textured growth according to claim 1, wherein when RE is Y, the preset temperature control program is that the temperature is raised to 1035-1042 ℃ at 60-70 ℃ per hour, the temperature is kept for 1.5-2.5 hours, the temperature is reduced to 993-1000 ℃ at 18-28 ℃ per hour, and then the temperature is reduced to 968-983 ℃ at 0.2-0.4 ℃ per hour.
  8. 8. The method of preparing superconducting bulk material by top-seeded melt textured growth according to claim 1, wherein when the RE is Sm, the preset temperature control program is to raise the temperature to 1065-1073 ℃ at 60-70 ℃ per hour, keep the temperature for 1.5-2.5 hours, then lower the temperature to 1050-1058 ℃ at 18-28 ℃ per hour, and then lower the temperature to 1030-1040 ℃ at 0.2-0.4 ℃ per hour.
  9. 9. The method of preparing superconducting bulk by top seeded melt textured growth according to claim 1, wherein the MgO-doped NdBCO seed has a size of 1 x 1mm 3 -2×2×2mm 3 .
  10. 10. A superconducting block, characterized in that it is prepared by the method of any one of claims 1-9.

Description

Method for preparing superconducting bulk by top seed crystal fusion texture growth and superconducting bulk Technical Field The invention belongs to the technical field of superconducting materials, and particularly relates to a method for preparing a superconducting block by melting texture growth of a top seed crystal and the superconducting block. Background RE-Ba-Cu-O (REBCO, RE is rare earth element Y, gd, sm, nd, etc.) series superconductive blocks have high magnetic levitation force, high critical transition temperature, large resistance to current carrying capacity, etc., and have very wide application prospects in the aspects of superconductive magnetic levitation, superconductive motors, superconductive flywheel energy storage, etc. In the process of preparing REBCO superconducting bulk, the top seed infiltration growth method (TSIG) adopted in the past needs to prepare more than two kinds of powder, such as REBa 2Cu3O6.5、RE2BaCuO5、Ba3Cu5O8, in advance, so that a large amount of time is consumed, the process is complicated, and meanwhile, certain waste is caused to the powder. In the prior art, although only one powder (BaCuO 2) is adopted to prepare the REBCO superconducting block, an infiltration growth method is adopted, and two precursors of a solid phase and a liquid phase are needed to be pressed, so that the process is complex and the cost is higher, and therefore, development of a fused texture growth method which only needs one powder is needed to prepare the superconducting block so as to simplify the process and reduce the cost is needed. Disclosure of Invention The invention aims to provide a method for preparing a superconducting bulk material by melt texture growth of a top seed crystal and the superconducting bulk material, so as to solve the problems. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: The application provides a method for preparing a superconducting block by melting texture growth of a top seed crystal, which comprises the following steps: Mixing RE 2O3、BaCuO2 and CuO, and pressing to obtain a precursor block, wherein RE is a rare earth element, the molar ratio of RE 2O3：BaCuO2 to CuO is 1:x:1, and x is 2.3-3.0; Pressing Yb 2O3 or Y 2O3 powder to obtain a support gasket; Sequentially superposing an Al 2O3 plate, an MgO single crystal, a support gasket, a precursor block and an NdBCO seed crystal doped with MgO from bottom to top, and assembling to obtain a blank; heating the blank body to 900-910 ℃ at the speed of 80-110 ℃ per hour, preserving the temperature for 8-10 hours, then performing heat treatment by a preset temperature control program corresponding to rare earth elements for preparing superconducting blocks, and finally cooling to room temperature along with furnace temperature to obtain REBCO superconducting blocks; And performing oxygen permeation treatment on the REBCO superconducting bulk material to obtain the superconducting bulk material with single domain texture. Optionally, the method includes: Mixing barium carbonate and copper oxide according to a molar ratio of 1:1, and ball milling for 4-5 hours to obtain mixed powder; And calcining the mixed powder, then re-ball milling, and repeating the calcining and ball milling for at least three times to obtain BaCuO 2 powder. Optionally, the calcination conditions are calcination at 900-920 ℃ for 24-28 hours. Optionally, the oxygen permeation treatment comprises cooling REBCO superconducting bulk material from 430 ℃ to 350 ℃ in a circulating oxygen environment, and annealing for 195-205 hours. Optionally, the RE 2O3 is a rare earth oxide, including any one of Y 2O3、Gd2O3、Sm2O3 and the like. Optionally, when the RE is Gd, the preset temperature control program is that the temperature is raised to 1050-1058 ℃ at 60-70 ℃ per hour, the temperature is kept for 1.5-2.5 hours, then the temperature is reduced to 1030-1035 ℃ at the rate of 18-28 ℃ per hour, and then the temperature is reduced to 1005-1018 ℃ at the rate of 0.2-0.4 ℃ per hour. Optionally, when RE is Y, the preset temperature control program is that the temperature is raised to 1035-1042 ℃ at 60-70 ℃ per hour, the temperature is kept for 1.5-2.5 hours, the temperature is lowered to 993-1000 ℃ at 18-28 ℃ per hour, and then the temperature is lowered to 968-983 ℃ at 0.2-0.4 ℃ per hour. Optionally, when the RE is Sm, the preset temperature control program is that the temperature is raised to 1065-1073 ℃ at the temperature of 60-70 ℃ per hour, the temperature is kept for 1.5-2.5 hours, the temperature is reduced to 1050-1058 ℃ at the speed of 18-28 ℃ per hour, and the temperature is reduced to 1030-1040 ℃ at the speed of 0.2-0.4 ℃ per hour. Optionally, the diameters of the precursor block and the support pad are the same. Optionally, the MgO single crystal has a height of 2-10mm. Optionally, the number of the MgO single crystals is more than 3 (the MgO single crystals are stable to support and have no