Method of preparing MgB
View Patent ↗Disclosed herein is a method of preparing a MgB 2 superconducting wire and the MgB 2 superconducting wire prepared thereby. The method comprising rolling a raw powder by using a powder rolling method. According to the method of the present invention has an effect of increasing an effective area where superconducting current can flow by improvement of the connectivity of a MgB 2 superconducting powder and achievement of high density through a powder rolling process, and maintaining an uniform current value even in a large length because of the improvement of the connectivity.
1. A method of preparing a MgB 2 superconducting wire, the method comprising the steps of:
preparing a raw powder for the MgB 2 superconducting wire;
providing the raw powder between a pair of rolling rolls without a tube for powder roll compaction, wherein the raw powder is provided through an outlet of a hopper that is positioned adjacent to an inlet of the rolling rolls; and
rolling the raw powder to compact it and produce the MgB 2 superconducting wire.
2. The method as set forth in claim 1 , wherein the raw powder is selected from the group consisting of a pre-reacted MgB 2 powder, a mixed powder of magnesium and boron, and a powder in which a dopant is added to the mixed powder.
3. The method as set forth in claim 2 , wherein the dopant is selected from the group consisting of SiC, carbon nanotubes, hydrocarbons, silicon oil, a malic acid, tin, and silver.
4. The method as set forth in claim 1 , further comprising coating a metal sheath simultaneously with rolling the raw powder to compact it.
5. The method as set forth in claim 4 , wherein the coated metal sheath is a powder form or a metal plate form.
6. The method as set forth in claim 1 , wherein the rolling rolls are cold or hot rolling rolls.
7. The method as set forth in claim 1 , wherein the preparing method further comprises a process of heat treating after rolling.
8. The method as set forth in claim 7 , wherein the heat treatment is performed in a pure Ar gas or a mixed gas of Ar and about 4 vol. % to about 10 vol. % of H 2 .
9. The method as set forth in claim 7 , wherein the heat treatment is performed at a temperature range of about 600° C. to about 1000° C.
10. A method of preparing a MgB 2 superconducting wire, the method comprising the steps of:
preparing a raw powder for the MgB 2 superconducting wire;
providing the raw powder between a pair of rolling rolls for powder roll compaction,
wherein the raw powder is not within a tube when provided between the pair of rolling rolls; and
rolling the raw powder to compact it and produce the MgB 2 superconducting wire.
11. The method as set forth in claim 10 , wherein the raw powder is selected from the group consisting of a pre-reacted MgB 2 powder, a mixed powder of magnesium and boron, and a powder in which a dopant is added to the mixed powder.
12. The method as set forth in claim 10 , wherein the dopant is selected from the group consisting of SiC, carbon nanotubes, hydrocarbons, silicon oil, a malic acid, tin, and silver.
13. The method as set forth in claim 10 , further comprising coating a metal sheath simultaneously with rolling the raw powder to compact it.
14. The method as set forth in claim 13 , wherein the coated metal sheath is a powder form or a metal plate form.
15. The method as set forth in claim 10 , wherein the rolling rolls are cold or hot rolling rolls.
16. The method as set forth in claim 10 , wherein the preparing method further comprises a process of heat treating after rolling.
17. The method as set forth in claim 16 , wherein the heat treatment is performed in a pure Ar gas or a mixed gas of Ar and about 4 vol. % to about 10 vol. % of H 2 .
18. The method as set forth in claim 16 , wherein the heat treatment is performed at a temperature range of about 600° C. to about 1000° C.