CN101168442A - High-performance MgB2 superconducting material and preparation method thereof - Google Patents

High-performance MgB2 superconducting material and preparation method thereof Download PDF

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CN101168442A
CN101168442A CNA2007101223990A CN200710122399A CN101168442A CN 101168442 A CN101168442 A CN 101168442A CN A2007101223990 A CNA2007101223990 A CN A2007101223990A CN 200710122399 A CN200710122399 A CN 200710122399A CN 101168442 A CN101168442 A CN 101168442A
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sic
mgb
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superconducting
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CN101168442B (en
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张现平
马衍伟
高召顺
王栋梁
王雷
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Institute of Electrical Engineering of CAS
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Abstract

The invention relates to an MgB2 superconductive material, which is characterized in being composed of Mg, B, C, and SiC. And a relative preparation is characterized in that according to mol ratio (0.8-0.975):(1.8-1.95):(0.010-0.15):(0.010-0.15) to prepare and mix Mg powder, B powder, C nanometer powder, and SiC nanometer powder uniformly to be filled into an iron tube or iron-copper composite tube to be sealed, rotationally forges, draws and rolls to obtain MgB2 superconductive material containing C and SiC nanometer powder, or tablets the raw powder mixed uniformly via a tablet press, to obtain MgB2 superconductive block containing C and SiC nanometer powder, arranges obtained band or block in a vacuum furnace, vacuums and fills argon gas, keeps temperature for 0.2-3h at 600-1200DEG C, and obtains MgB2 superconductive material containing C nanometer powder and SiC nanometer powder. The inventive MgB2 superconductive material has better performance under magnetic field, with better repeatability.

Description

A kind of high-performance MgB 2Superconducting material and preparation method thereof
Technical field
The present invention relates to a kind of high-performance MgB 2Superconducting material and preparation method thereof.
Background technology
MgB 2Have higher transition temperature, bigger coherence length, crystal boundary and do not have weak connection, characteristics such as simple in structure, with low cost.These advantages make MgB 2Become the strongest rival of material who is applied in the 20K-30K temperature range.Particularly in a low field, as at magnet for magnetic resonant imaging application facet, MgB 2Show great advantage, had data to show, MgB 2Practicability will bring billions of economic benefits, and owing to can under the refrigeration mechanism cool condition, work MgB 2Application will promote the popularization of magnetic resonance imager greatly, have crucial meaning for the raising of the vast rural people's medical level of China.
Yet the MgB of present preparation 2The critical current density of material is compared also lower with cryogenic superconductor with the A15 superconductor.Critical current density is the key characteristic that can a kind of superconducting material of decision large-scale application, film or block MgB 2Superconductor under null field, have higher critical current density (when 4.2K, J c>10 6A/cm 2When 20K, J c>5 * 10 5A/cm 2), but in certain magnetic field, MgB 2What critical current density was rapid along with the increase of magneticstrength reduces, and shows the irreversible field than enlightening, only is 4-5T as irreversible the value of pure MgB2 superconductor under 20K.In order to improve MgB 2Critical current density under certain magnetic field can adopt methods such as neutron (proton) bombardment, chemical corrosion, mechanical workout, doping, and since mix have easier fast, can carry out characteristics such as even modification, become present raising MgB 2The main method of material superconductivity.
So far, improve MgB by mixing 2The best dopant of material property effect is nanometer C (Ma Y W etc., the Significantly enhanced critical current densities in MgB that people such as Ma Yanwei finds 2Tapes made by ascaleable nanocarbon addition route, Applied Physics Letters, 88 (2006) 072502) and people such as the Dou Shixue nano SiC (Dou.S.X etc., the Enhancement of the critical current density and fluxpinning of MgB that attempt 2Superconductor by nanoparticle SiC doping, AppliedPhysics Letters, 81 (2002) 3419).A large amount of experimental results show that nanometer C and nano SiC doping can increase substantially MgB 2The upper critical field of bulk and irreversible field are introduced a large amount of effective pinning center simultaneously, thereby are made MgB 2The critical current density of material in magnetic field also is improved.After for example mixing through SiC, MgB 2The critical current density of band can reach 2.5 * 10 4A/cm 2[Matsumoto A etc., Effect of impurity additions on the microstructures andsuperconducting properties of in situ processed MgB 2Tapes, Supercond.Sci.Technol.17 (2004) S319-S323)], through MgB after the C doping 2The critical current density of band can reach 2.1 * 10 4A/cm 2[Ma Y W etc., Large irreversibility field in nanoscale C-doped MgB 2/ Fe tape conductors, Supercond.Sci.Technol.20 (2007) L5-L7)].
Summary of the invention
The objective of the invention is in order to overcome existing MgB 2Lower critical current density lower shortcoming in superconducting material magnetic field provides a kind of high-performance MgB that has 2Superconducting material and preparation method thereof.It is composite mixed that preparation method of the present invention adopts nanometer C and these two kinds the most effective dopants of SiC to carry out, and makes MgB 2Superconducting material obtains the raising effect of two kinds of dopants simultaneously, and then significantly improves MgB 2The critical current density of material.
MgB of the present invention 2The superconducting material component is Mg, B, C and SiC, and its constitutive molar ratio is: Mg: B: C: SiC=(0.8-0.975): (1.6-1.95): (0.010-0.15): (0.010-0.15).
Preparation method of the present invention is as follows:
The present invention adds nanometer C powder at raw material Mg powder in the B powder, nano SiC powder, material purity are commercially available chemical pure, and the mol ratio of its composition is: Mg: B: C: SiC=(0.8-0.975): (1.6-1.95): (0.010-0.15): (0.010-0.15).
With the Mg powder, the B powder, nanometer C powder, the nano SiC powder is according to mol ratio (0.8-0.975): (1.8-1.95): (0.010-0.15): (0.010-0.15) prepare and mix, pack in iron pipe or the iron copper multiple-unit tube sealing back with 10% deformation rate successively swage in order, drawing, rolling, obtain containing the MgB of C and SiC 2Superconducting line strips.Perhaps the raw material powder that mixes is carried out compressing tablet with tabletting machine, obtain containing the MgB of C and SiC 2Superconductive block.The wire strip or the bulk that obtain are placed in the vacuum oven, charge into argon gas after vacuumizing,, finally obtain containing the MgB of C and SiC 600 ℃-1200 ℃ insulations 0.5-3 hour 2Superconducting material.
In general, improve MgB 2The approach of material superconductivity has following two kinds, and a kind of is to improve MgB 2The upper critical field of material and irreversible field, another kind is to improve MgB 2The flux pinning ability of material.C and SiC are composite mixed for improving MgB 2Current capability under the wire strip High-Field has good effect, is that mainly it has following characteristics:
At first, C and SiC mix and have the effect of crystal grain thinning.The existence of a large amount of crystal boundaries has a very important role for the flux pinning ability that improves material in the crystal.The second phase impurity of introducing that mixes in addition also can play the effect that improves the flux pinning ability.
Secondly, lattice distortion that C and SiC doping can cause and C substitute B's, improve MgB 2The upper critical field of material and irreversible field.Simultaneously, experiment confirm has been arranged, C or SiC mix for improving MgB 2The compactness of material has remarkable effect.
The present invention adopts commercially available Mg powder, B powder, C nano powder, and the SiC nano powder adopts above-mentioned molar ratio, preparation technology and thermal treatment process can prepare the MgB that contains C and SiC that performances such as critical current density, irreversible field all are significantly improved 2Superconducting line strips.MgB with the inventive method preparation 2The critical current density of superconducting tape is 3.6 * 10 4A/cm 2(4.2K, 10T) about, and repeatability is fine, (4.2K, under the 10T condition, current density reaches 2.5 * 10 far above the best level of present World Report 4A/cm 2) [Matsumoto A etc., Effect of impurity additions on themicrostructures and superconducting properties of in situ-processed MgB 2Tapes, Superconductor Science and Technology, 17 (2004) S319], and the cost expense is far below people's such as Matsumoto A product.If the long wire strip of the MgB2 that this method is used to prepare will greatly promote MgB 2The industrialization process of material.
Embodiment
Example 1
Preparation (MgB 2) 0.92C 0.04SiC 0.04Superconducting tape.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.92: 1.84: 0.04: 0.04 accurate weighing also mixes, the diameter of packing into be in 8 millimeters the iron pipe sealing back with 10% deformation rate swage in order, drawing, rolling, obtain wide 3.7 millimeters, thick 0.5 millimeter band.With band 900 ℃ of insulations 1 hour in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting tape.The critical current density of the band that makes is 3.6 * 10 4A/cm 2(4.2K, 10T).
Example 2
Preparation (MgB 2) 0.975C 0.015SiC 0.013Superconducting tape.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.975: 1.95: 0.015: 0.013 accurate weighing also mixes, the diameter of packing into be in 8 millimeters the iron pipe sealing back with 10% deformation rate swage in order, drawing, rolling, obtain wide 3.7 millimeters, thick 0.5 millimeter band.With band 800 ℃ of insulations 1 hour in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting tape.The critical current density of the band that makes is 8.4 * 10 3A/cm 2(4.2K, 14T).
Example 3
Preparation (MgB 2) 0.8C 0.1SiC 0.1Superconducting wire.With the Mg powder, the B powder, nanometer C powder, nano SiC powder were according to mol ratio 0.8: 1.6: 0.1: 0.1 accurate weighing also mixes, the diameter of packing into be in 20 millimeters the iron pipe sealing back with 10% deformation rate swage in order, drawing, obtain diameter and be 1.0 millimeters wire rod.With wire rod 700 ℃ of insulations 0.5 hour in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting wire.
Example 4
Preparation (MgB 2) 0.95C 0.015SiC 0.035Superconducting tape.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder is according to mol ratio accurate weighing in 0.95: 1.9: 0.01 5: 0.035 and mix, the diameter of packing into be in 16 millimeters the iron pipe sealing back with 10% deformation rate swage in order, drawing, rolling, obtain wide 3.7 millimeters, thick 0.5 millimeter band.With band 700 ℃ of insulations 0.5 hour in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting tape.
Example 5
Preparation (MgB 2) 0.95C 0.025SiC 0.025Superconducting tape.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.95: 1.9: 0.025: 0.025 accurate weighing also mixes, the external diameter of packing into be in 12 millimeters the iron copper multiple-unit tube sealing back with 10% deformation rate swage in order, drawing, rolling, obtain wide 3.7 millimeters, thick 0.5 millimeter band.With band 650 ℃ of insulations 1 hour in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting tape.
Example 6
Preparation (MgB 2) 0.8C 0.085SiC 0.115Superconducting tape.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.8: 1.6: 0.085: 0.115 accurate weighing also mixes, the diameter of packing into be in 8 millimeters the iron pipe sealing back with 10% deformation rate swage in order, drawing, rolling, obtain wide 3.7 millimeters, thick 0.5 millimeter band.With band 600 ℃ of insulations 1.5 hours in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting tape.
Example 7
Preparation (MgB 2) 0.8C 0.115SiC 0.085Superconducting wire.With the Mg powder, the B powder, nanometer C powder, nano SiC powder were according to mol ratio 0.8: 1.6: 0.115: 0.085 accurate weighing also mixes, the external diameter of packing into be in 8 millimeters the iron copper multiple-unit tube sealing back with 10% deformation rate swage in order, drawing, obtain diameter and be 1.0 millimeters wire rod.With band 650 ℃ of insulations 1 hour in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting wire.
Example 8
Preparation (MgB 2) 0.975C 0.02SiC 0.005Superconducting tape.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.975: 1.95: 0.02: 0.005 accurate weighing also mixes, the diameter of packing into be in 8 millimeters the iron pipe sealing back with 10% deformation rate swage in order, drawing, rolling, obtain wide 3.7 millimeters, thick 0.5 millimeter band.With band 700 ℃ of insulations 0.5 hour in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting tape.
Example 9
Preparation (MgB 2) 0.975C 0.015SiC 0.01Superconducting tape.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.975: 1.95: 0.015: 0.01 accurate weighing also mixes, the external diameter of packing into be in 18 millimeters the iron copper multiple-unit tube sealing back with 10% deformation rate swage in order, drawing, rolling, obtain wide 3.7 millimeters, thick 0.5 millimeter band.With band 600 ℃ of insulations 1.5 hours in the argon gas vacuum oven of atmosphere that flows, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconducting tape.
Example 10
Preparation (MgB 2) 0.95C 0.025SiC 0.015Superconductive block.With the Mg powder, the B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.95: 1.9: 0.025: 0.015 accurate weighing also mixes, carry out in the normal pressure argon atmospher, carrying out sintering behind the compressing tablet with tabletting machine, 800 ℃ of insulations 2 hours, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconductive block.
Example 11
Preparation (MgB 2) 0.8C 0.15SiC 0.05Superconductive block.With the Mg powder, B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.8: 1.6: 0.15: 0.05 accurate weighing also mixes, and carries out carrying out sintering behind the compressing tablet in the normal pressure argon atmospher with tabletting machine, 600 ℃ of insulations 1.5 hours, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconductive block.
Example 12
Preparation (MgB 2) 0.9C 0.015SiC 0.085Superconductive block.With the Mg powder, B powder, nanometer C powder, the nano SiC powder was according to mol ratio 0.9: 1.8: 0.015: 0.085 accurate weighing also mixes, and carries out carrying out sintering behind the compressing tablet in the normal pressure argon atmospher with tabletting machine, 900 ℃ of insulations 3 hours, in vacuum oven, be cooled to room temperature then, obtain containing the MgB of C and SiC 2Superconductive block.
This technology is used in the explanation of above example can the good wire strip of processability, is MgB 2The superconducting material practical application provides material foundation.

Claims (3)

1. high-performance MgB 2Superconducting material is characterized in that its component is Mg, B, C and SiC, and its constitutive molar ratio is: Mg: B: C: SiC=(0.8-0.975): (1.6-1.95): (0.010-0.15): (0.010-0.15).
2. one kind prepares the described MgB of claim 1 2The method of superconducting material, it is characterized in that, with the Mg powder, the B powder, nanometer C powder, nano SiC powder are according to mol ratio (0.8-0.975): (1.8-1.95): (0.010-0.15): (0.010-0.15) prepare and mix, in pack into iron pipe or the iron copper multiple-unit tube after the sealing, deformation rate with 10% is successively swaged in order, drawing, rolling, obtains containing the MgB of C and SiC 2Superconducting wire or band; Perhaps the raw material powder that mixes is carried out compressing tablet with tabletting machine, obtain containing the MgB of C and SiC 2Superconductive block.
3. according to the described MgB of claim 2 2The preparation method of superconducting material in the wire strip or bulk placement vacuum oven that it is characterized in that obtaining, charges into argon gas after vacuumizing, and 600 ℃-1200 ℃ insulations 0.2-3 hour, finally obtains containing the MgB of C and SiC 2Superconducting material.
CN2007101223990A 2007-09-25 2007-09-25 High-performance MgB2 superconducting material and preparation method thereof Expired - Fee Related CN101168442B (en)

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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102074309A (en) * 2010-11-28 2011-05-25 上海大学 Method for preparing magnesium diboride composite superconducting material
CN102190311A (en) * 2010-03-12 2011-09-21 北京大学 Method for preparing MgB2 superconducting material on basis of Mg(BH4)2 precursor
CN101591172B (en) * 2009-06-26 2012-04-18 天津大学 Metal Sn doped MgB2 superconductor and high-temperature rapid preparation method thereof
CN102543304A (en) * 2011-12-20 2012-07-04 东南大学 Method for preparing MgB2 superconducting wire
CN102718230A (en) * 2012-05-17 2012-10-10 天津大学 Layered MgB2 crystal structure and synthetic method thereof
CN106205861A (en) * 2016-06-29 2016-12-07 西北有色金属研究院 A kind of preparation method of graphene-supported multi-element doping magnesium diboride superconductive bulk

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Publication number Priority date Publication date Assignee Title
US20060093861A1 (en) * 2004-10-29 2006-05-04 The Penn State Research Foundation Method for producing doped, alloyed, and mixed-phase magnesium boride films
CN1933036A (en) * 2005-09-13 2007-03-21 中国科学院电工研究所 MgBz superconducting material and producing method thereof
CN1986407A (en) * 2005-12-23 2007-06-27 中国科学院电工研究所 Corbon-containing superconductive MgB2 material and its preparing process
CN1929044B (en) * 2006-08-07 2010-09-22 中国科学院电工研究所 MgB2 superconductive material containing Si element and C element and its preparing method

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101591172B (en) * 2009-06-26 2012-04-18 天津大学 Metal Sn doped MgB2 superconductor and high-temperature rapid preparation method thereof
CN102190311A (en) * 2010-03-12 2011-09-21 北京大学 Method for preparing MgB2 superconducting material on basis of Mg(BH4)2 precursor
CN102190311B (en) * 2010-03-12 2013-03-06 北京大学 Method for preparing MgB2 superconducting material on basis of Mg(BH4)2 precursor
CN102074309A (en) * 2010-11-28 2011-05-25 上海大学 Method for preparing magnesium diboride composite superconducting material
CN102543304A (en) * 2011-12-20 2012-07-04 东南大学 Method for preparing MgB2 superconducting wire
CN102543304B (en) * 2011-12-20 2013-07-31 东南大学 Method for preparing MgB2 superconducting wire
CN102718230A (en) * 2012-05-17 2012-10-10 天津大学 Layered MgB2 crystal structure and synthetic method thereof
CN106205861A (en) * 2016-06-29 2016-12-07 西北有色金属研究院 A kind of preparation method of graphene-supported multi-element doping magnesium diboride superconductive bulk
CN106205861B (en) * 2016-06-29 2017-05-10 西北有色金属研究院 Preparation method for graphene-loaded multielement-doped magnesium diboride superconducting bulk material

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