Ultra-lightweight superconducting wire based on Mg, B, Ti and Al

Kòváč, Pavol; Hušek, I; Rosová, A.; Kulich, M; Kováč, J.; Melíšek, T; Kopera, Ľ; Balog, Martin; Krížik, Peter

doi:10.1038/s41598-018-29354-1

Cited by 21 publications

(14 citation statements)

References 30 publications

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“…The set of single-core MgB 2 wires has been made by identical IMD process. The metallic tubes with purity 99.9% of diameter 9.0/6.2 mm were used for outer sheath: from Cu (named Cu-A) and from Al with 1.5 vol % Al 2 O 3 metal matrix composite (named Al-B) and Al with 3.1 vol % Al 2 O 3 (named Al-C) prepared by powder metallurgy [14][15][16] are described by table 1. HV0.05 is the micro-hardness measured for these sheath materials in as-deformed state.…”

Section: Methodsmentioning

confidence: 99%

MgB₂ cables made of thin wires manufactured by IMD process

Kòváč¹,

Kopera²,

Hain³

et al. 2020

Supercond. Sci. Technol.

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This paper presents the properties of cables made of thin MgB2 wires with different sheaths manufactured by IMD process. Strong effect of the outer sheath on the Je(B) performance was observed and the best properties were obtained for the strongest Cu sheath. It was found that the transversal and longitudinal cables uniformity affects the critical currents in MgB2 wires made by IMD considerably. We have analyzed the quench dynamics in Rutherford cables with Al+1.5%Al2O3 sheath, when subjected to heat disturbances. Quench triggered in the strands in direct contact with the heater, observing important delays in quench development among strands. Low AC losses were measured for the extra-light Rutherford cable with Ti barrier and Al+1.5%Al2O3 sheath due to an increased barrier resisitivity and surface Al sheath oxidation, which reduces coupling current loss component effectivelly.

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Section: Methodsmentioning

confidence: 99%

MgB₂ cables made of thin wires manufactured by IMD process

Kòváč¹,

Kopera²,

Hain³

et al. 2020

Supercond. Sci. Technol.

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“…These Al 2 O 3 particles which act as dispersoids in the Al matrix, will influence the microstructure (grain structures) slightly differently. On annealing, the bigger Al 2 O 3 dispersoids may impose smaller stabilizing effect on the low angle grain boundaries of Al [10]. The microstructural features which will be slightly different in the case of can affect the mechanism of the critical current flowing through the wire, and hence gets reflected on the I c -B curve which has a slightly different slope than the other two wires.…”

Section: Critical Current and I-v Characteristics Of Mgb 2 Wiresmentioning

confidence: 99%

“…Additionally, Nb may not be a good option to be used as a barrier with Al + Al 2 O 3 sheath because of higher reaction kinetics between Nb and Al [7]. On the other hand, the sufficiently ductile Ta is reported to show a minimal reactivity with Mg [10]. Few authors of this article have found that Ti offers the best core uniformity and the highest powder density prior to the heat treatment among the others [19], and produces a superconducting wire which is considerably lighter when combined with the (Al + Al 2 O 3 ) stabilizer sheath [10].…”

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confidence: 99%

“…On the other hand, the sufficiently ductile Ta is reported to show a minimal reactivity with Mg [10]. Few authors of this article have found that Ti offers the best core uniformity and the highest powder density prior to the heat treatment among the others [19], and produces a superconducting wire which is considerably lighter when combined with the (Al + Al 2 O 3 ) stabilizer sheath [10]. However, a detailed analyses on the reactions between MgB 2 -barrier (Ta or Ti) and barrier-(Al + Al 2 O 3 ) stabilizer sheath are yet to be addressed.…”

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confidence: 99%

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Comparison of interfacial and critical current behaviour of Al+Al2O3 sheathed MgB2 wires with Ta and Ti diffusion barriers

Santra

Grovenor

Speller

et al. 2019

Journal of Alloys and Compounds

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The intermetallic magnesium diboride (MgB 2) superconductor compound has higher critical temperature (T c) of 39 K than the conventional low temperature superconductors [1]. It also offers advantages of larger coherence length (∼5 nm), absence of weak-link at the grain boundaries [2], cost-effectiveness [1] and almost an isotropic behaviour [3]. As a result, manufacturing MgB 2 wires with high critical current is of scientific interest for various engineering applications [4,5]. The effective process for producing nearly stoichiometric and dense MgB 2 wires is the internal magnesium diffusion (IMD) technique [6]. In the IMD technique, a solid magnesium (Mg) rod is surrounded by the boron powder, and the MgB 2 compound forms when Mg infiltrates into the boron (B) compacted powder [6]. The MgB 2 wires should be stabilized thermally by a highly conductive metal, and be able to provide the mechanical strength [7]. Cu is used as the outer stabilizing sheath for the commercially produced NbTi and Nb 3 Sn superconducting wires [8]. However, the Cu-sheathed MgB 2 composite wire produces a deleterious Cu 2 Mg layer at the MgB 2-Cu interface [9], and therefore the transport current density decreases [10]. Research demonstrates that the high thermal and electrical conductivity of Al can be put to use for an outer stabilizer sheath, and is mechanically reinforced too, when alloyed with ultrafine grained Al 2 O 3 [11]. It is important that the stabilizer sheath material does not react with the formed MgB 2 and produce any reaction layer which often can be non-superconductive, and as a result, the current carrying properties of the MgB 2 Comparison of interfacial and critical current behaviour of Al+Al 2 O 3 sheathed MgB 2 wires with Ta and Ti diffusion barriers S. Santra a, *

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“…In this regard, round MgB chemically doped wires are of particular importance, not only due to their superior and upper critical field, , but because the powder-in-tube process allows an easy manufacturing of multicore (a.k.a. multifilamentary) wires 9 , 10 , as precursors of high-power AC/DC applications such as, power transmission cables 11 – 13 , rotary machines 14 – 17 , energy-storage devices 18 , MRI cryogen-free magnets 19 – 21 , fusion reactors 22 , and the large scale commercialization of high-current SC links for CERN 23 , 24 .…”

Section: Introductionmentioning

confidence: 99%

Maximum reduction of energy losses in multicore MgB2 wires by metastructured soft-ferromagnetic coatings

Kapolka

2022

Sci Rep

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When compared with rare-earth coated conductors, magnesium diboride superconducting cables are known to show significant advantages by cost and easy production. However, the inherent difficulty for achieving a significant reduction of their magnetization losses in multifilamentary wires, without degrading the high critical current density that is so characteristic of the monowire, is considered as one of the major drawbacks for their practical use in high power density applications. Being this one of the major markets for superconducting cables, from fundamental principles and computational optimization techniques, in this paper we demonstrate how the embedding of the superconducting filaments into soft-ferromagnetic metastructures can render to their full magnetic decoupling, and therefore, to the maximum reduction of the energy losses that can be achieved without deteriorate the critical current density of the cable. The designed multifilamentary metastructure is made of NbTi coated MgB2 superconducting filaments in a Cu-matrix, serving as a reference for validating our model with actual experimental measurements in monowires and multifilamentary wires. The novelty in our computationally aided multifilamentary wires, is that each one of the filaments is embedded within a thin metastructure made of a soft-ferromagnetic layer and a resistive layer. We have found that for soft-ferromagnetic layers with magnetic permeabilities in the range of $$\mu _{r}=$$ μ r = 20–100, nearly a full magnetic decoupling between the superconducting filaments can be achieved, leading to efficiencies higher than $$92\%$$ 92 % , and an overall reduction of the AC-losses (including eddy currents at the Cu-matrix) higher than $$50\%$$ 50 % .

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Ultra-lightweight superconducting wire based on Mg, B, Ti and Al

Cited by 21 publications

References 30 publications

MgB₂ cables made of thin wires manufactured by IMD process

MgB₂ cables made of thin wires manufactured by IMD process

Comparison of interfacial and critical current behaviour of Al+Al2O3 sheathed MgB2 wires with Ta and Ti diffusion barriers

Maximum reduction of energy losses in multicore MgB2 wires by metastructured soft-ferromagnetic coatings

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Ultra-lightweight superconducting wire based on Mg, B, Ti and Al

Cited by 21 publications

References 30 publications

MgB2 cables made of thin wires manufactured by IMD process

MgB2 cables made of thin wires manufactured by IMD process

Comparison of interfacial and critical current behaviour of Al+Al2O3 sheathed MgB2 wires with Ta and Ti diffusion barriers

Maximum reduction of energy losses in multicore MgB2 wires by metastructured soft-ferromagnetic coatings

Contact Info

Product

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MgB₂ cables made of thin wires manufactured by IMD process

MgB₂ cables made of thin wires manufactured by IMD process