Review of synthesis of high volumetric density, low gravimetric density MgB2 bulk for potential magnetic field applications

Zhang, Zili; MacManus‐Driscoll, Judith L.; Suo, Hongli; Wang, Qiuliang

doi:10.1016/j.supcon.2022.100015

Cited by 15 publications

(11 citation statements)

References 244 publications

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“…Focusing on the values measured at the center of the disc ( r = 0) and at a distance from the disc surface z = 1.5 mm, at 20 K, we obtained trapped field values of

= 1.37 T, while

= 1.05 T and

= 0.64 T were obtained at temperatures T = 25 K and T = 30 K, respectively. The achieved results are comparable with those obtained in literature, considering samples with an aspect ratio ( r/h ) and experimental conditions similar to ours and reported in [ 19 , 55 ]. Notably, the

curves measured at positions #1 ( r = 8 mm, left side with respect to the disc’s center, see Figure 2 b) and #8 ( r = 8.5 mm, right side) superimpose each other.…”

Section: Results and Discussionsupporting

confidence: 91%

“…Furthermore, an additional improvement in trapping field ability has been obtained, creating hybrid arrangements wherein ferromagnetic (FM) components are superimposed or integrated into the superconducting (SC) ones [ 13 , 14 , 15 , 16 ]. Among superconductors, cost-effectiveness, absence of toxic elements, lack of reliance on rare earth elements, and the ability to transport high critical current across randomly oriented grain boundaries make MgB 2 a good candidate for trapped field applications [ 17 , 18 , 19 ]. In addition, recent progresses in bulk fabrication techniques has allowed for the manufacturing of MgB 2 bulks with high trapped field values even in small-sized samples [ 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

“…In addition, recent progresses in bulk fabrication techniques has allowed for the manufacturing of MgB 2 bulks with high trapped field values even in small-sized samples [ 20 , 21 ]. It was reported that the critical current densities and trapped field depend on the density and homogeneity of the MgB 2 superconducting material and pinning centers [ 19 , 22 ]. Studies indicated that the homogeneity and density of the superconducting MgB 2 material and the density of pinning centers can be improved by thermal treatment under high isostatic pressure or by an increase of the density of the MgB 2 material before the synthesis reaction [ 23 , 24 , 25 ].…”

Section: Introductionmentioning

confidence: 99%

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Comparison of the Field Trapping Ability of MgB2 and Hybrid Disc-Shaped Layouts

Fracasso,

Gerbaldo,

Ghigo

et al. 2024

Materials

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Superconductors have revolutionized magnet technology, surpassing the limitations of traditional coils and permanent magnets. This work experimentally investigates the field-trapping ability of a MgB2 disc at various temperatures and proposes new hybrid (MgB2-soft iron) configurations using a numerical approach based on the vector potential (A→) formulation. The experimental characterization consists in measurements of trapped magnetic flux density carried out using cryogenic Hall probes located at different radial positions over the MgB2 sample, after a field cooling (FC) process and the subsequent removal of the applied field. Measurements were performed also as a function of the distance from the disc surface. The numerical modelling of the superconductor required the evaluation of the critical current density dependence on the magnetic flux density (Jc(B)) obtained through an iterative procedure whose output were successfully validated by the comparison between experimental and computed data. The numerical model, upgraded to also describe the in-field behavior of ARMCO soft iron, was then employed to predict the field-trapping ability of hybrid layouts of different shapes. The most promising results were achieved by assuming a hollow superconducting disc filled with a ferromagnetic (FM) cylinder. With such a geometry, optimizing the radius of the FM cylinder while the external dimensions of the superconducting disc are kept unchanged, an improvement of more than 30% is predicted with respect to the full superconducting disc, assuming a working temperature of 20 K.

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“…Focusing on the values measured at the center of the disc ( r = 0) and at a distance from the disc surface z = 1.5 mm, at 20 K, we obtained trapped field values of

= 1.37 T, while

= 1.05 T and

curves measured at positions #1 ( r = 8 mm, left side with respect to the disc’s center, see Figure 2 b) and #8 ( r = 8.5 mm, right side) superimpose each other.…”

Section: Results and Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Comparison of the Field Trapping Ability of MgB2 and Hybrid Disc-Shaped Layouts

Fracasso,

Gerbaldo,

Ghigo

et al. 2024

Materials

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“…After processing dense samples using different precursors and SPS molds, the densities of D1 (MgB 2 ), D2 (Mg + 2B), D3 (Mg + MgB 4 ) and D4 (Mg + 2B), were 2.62 g cm −3 , 2.49 g cm −3 , 2.4 g cm −3 and 2.46 g cm −3 , respectively. These values corresponds to 99%, 95%, 92% and 94% of the theoretical value [23], respectively. The different packing ratios can be related to the particles sizes and shapes of the starting powders, as well as to the chemical reactions occurring in the Mg + 2B and the Mg + MgB 4 powders during the processing stage.…”

Section: Characterization Of the Ds Mgb 2 Bulksmentioning

confidence: 75%

Overview of spark plasma synthesis and sintering of MgB₂ superconductor

Xing,

Bernstein,

Muralidhar

et al. 2023

Supercond. Sci. Technol.

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This study aims to investigate the flash sintering mechanisms of magnesium diborides using SPS and optimize the sintering process conditions. Three different precursor materials were used: i) commercial powder MgB2, ii) mixtures of magnesium and nano boron powder (Mg + 2B), and iii) mixtures of Mg and MgB4 powder for an "in-situ" reactive synthesis. The density of the obtained bulks exceeds 90 % of the theoretical density of the material. The structure and microstructure of the samples were analyzed using X-ray diffraction and SEM, which were correlated with their superconducting properties. The critical current density (Jc), pinning force (fp), and electrical resistivity (ρ) of the samples were also investigated. The results show that the in-situ reactive synthesis of MgB2 using magnesium and nano boron powder was the most effective method for producing high-quality samples with improved superconducting properties. The findings could lead to the development of more efficient methods for producing high-performance of MgB2 bulks.

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“…The conductors are likely to be multi-filament MgB 2 cables. These have a complex manufacturing process and, in general, are made into circuits using the 'form and react' method [21], whereby the 'green' wire must be shaped into a coil and then reacted in a furnace at around 700 • C to create the actual superconductor.…”

Section: Stator For 3 Mw Motormentioning

confidence: 99%

Additive manufacturing materials for structural optimisation and cooling enhancement of superconducting motors in cryo-electric aircraft

Lumsden,

Ludbrook,

Rogers Rehn

et al. 2023

Supercond. Sci. Technol.

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Superconducting electric motors offer the potential for low weight and high power in applications such as electric aircraft and high speed marine transport. Combined with renewably-sourced cryogenic fuels and advanced fuel cells they offer a path to zero-carbon mass transport. The proposed architectures of these extreme machines, operating at temperatures around 20K to 50K and employing very high alternating magnetic fields, require materials for the stator that are not electrically conducting and at the same time have good cryogenic structural performance. Additively manufactured (AM) materials can play a key role in these designs, and a collaboration between the Robinson Research Institute and AUT is studying the performance of a range of composite polymers in superconducting machine applications. There are significant challenges to be met, including understanding the effect of the build process on material properties at low temperatures, and also the effect of formulation changes on thermal properties.Additively manufactured metals can be employed in the rotor components, where the magnetic field fluctuations are very small for our synchronous designs. In this usage case, we can achieve dramatic reductions in the weight of the rotor assembly by minimising the number of joints and facilitating the design of multi-functional components in our helium cooled, vacuum cryostat architecture.Novel design solutions have been developed for several key components in our prototype machines and these are discussed, along with cryogenic testing results for selected additively manufactured polymers and composites. 

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Review of synthesis of high volumetric density, low gravimetric density MgB2 bulk for potential magnetic field applications

Cited by 15 publications

References 244 publications

Comparison of the Field Trapping Ability of MgB2 and Hybrid Disc-Shaped Layouts

Comparison of the Field Trapping Ability of MgB2 and Hybrid Disc-Shaped Layouts

Overview of spark plasma synthesis and sintering of MgB₂ superconductor

Additive manufacturing materials for structural optimisation and cooling enhancement of superconducting motors in cryo-electric aircraft

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Review of synthesis of high volumetric density, low gravimetric density MgB2 bulk for potential magnetic field applications

Cited by 15 publications

References 244 publications

Comparison of the Field Trapping Ability of MgB2 and Hybrid Disc-Shaped Layouts

Comparison of the Field Trapping Ability of MgB2 and Hybrid Disc-Shaped Layouts

Overview of spark plasma synthesis and sintering of MgB2 superconductor

Additive manufacturing materials for structural optimisation and cooling enhancement of superconducting motors in cryo-electric aircraft

Contact Info

Product

Resources

About

Overview of spark plasma synthesis and sintering of MgB₂ superconductor