The effect of the size of NbTi filaments on interfacial reactions and the properties of InSn-based superconducting solder joints

Santra, Sangeeta; Davies, Timothy; Matthews, G. P.; Liu, Junliang; Grovenor, C.R.M.; Speller, Susannah

doi:10.1016/j.matdes.2019.107836

Cited by 22 publications

(8 citation statements)

References 47 publications

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“…The addition of trace elements may decrease the diffusion rate of IMC by lowering the activity of Cu and Su elements or blocking the diffusion path of atoms in a liquid-solid reaction state. Additionally, the mechanical strength may be improved by a composite microstructure close to the prediction of the dispersion reinforcement theory [15][16][17][18][19][20]. However, the impact of Cr addition to the commercial Sn-0.7Cu solder on the initial formation and growth of IMCs is unexplored.…”

Section: Introductionmentioning

confidence: 90%

Nucleation and Morphology of Cu6Sn5 Intermetallic at the Interface between Molten Sn-0.7Cu-0.2Cr Solder and Cu Substrate

Son

Dong

Kim

et al. 2021

Metals

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The nucleation kinetics and morphology of Cu6Sn5 IMCs at the interface between a Sn-0.7Cu-0.2Cr solder and Cu substrate were investigated in this study. A Sn-0.7Cu solder was utilized as a reference to elucidate the impact of Cr addition. The mechanical properties of the solder joints were determined via ball-shear tests. Cu coupons were dipped in the molten solders for 1 and 3 s at 240–300 °C, and the morphological analyses were conducted via electron microscopy. Both the solders contained scallop-like Cu6Sn5 IMCs. The smallest Cu6Sn5 IMCs were observed at 260 °C in both the solders, and the particle size increased at 280 and 300 °C. The IMCs in the Sn-0.7Cu-0.2Cr solder were smaller and thinner than those in the Sn-0.7Cu solder at all the reaction temperatures. The thickness of the IMCs increased as the reaction temperature increased. Inverse C-type nucleation curves were obtained, and the maximum nucleation rate was observed at an intermediate temperature. The shear strengths of the Sn-0.7Cu-0.2Cr solder joints were higher than those of the Sn-0.7Cu solder joints. This study will facilitate the application of lead-free solders, such as Sn-0.7Cu-0.2Cr, in automotive electrical components.

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Section: Introductionmentioning

confidence: 90%

Nucleation and Morphology of Cu6Sn5 Intermetallic at the Interface between Molten Sn-0.7Cu-0.2Cr Solder and Cu Substrate

Son

Dong

Kim

et al. 2021

Metals

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“…The currently used technological lead-free solders (such as Bi-Sn-Ag, Bi-Sn, Sn-Zn, Ag-In) do not have good enough superconducting properties for persistent mode applications [5] even though they are promising for aerospace and some cryogenic applications. SnIn solders are potentially promising for joining NbTi wires for MRI magnets [6]. Previous studies clarified that SnIn (35:65) alloy showed the best superconducting properties among the chosen binary alloys according to the SnIn Phase Diagram in [2].…”

Section: Introductionmentioning

confidence: 99%

Demonstration of better superconducting performance in a solder with low lead content

Aksoy¹,

Çakır²,

Koparan³

et al. 2022

Supercond. Sci. Technol.

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Lead-free SnIn solders are promising for superconducting magnet applications. However, their superconducting properties are not as good as lead solders. In order to improve the superconducting performance of the Sn-In solders, researchers have investigated the superconducting properties of ternary systems such as Sn-In-Bi for solder joints. In this study, powders of Pb, Nb, AgCu and grapheme nano pellets in ratios 0.5-5 wt % have been added into SnIn (35:65) to investigate their microstructural, thermal and superconducting properties. The added materials enhanced the superconducting properties. We find that even low Pb additions showed a dramatic improvement in superconducting properties, with an increase in both Tc and Jc values up to 6.35 K and 1.47×104 A/m2, respectively. This shows that much lower Pb content superconducting solders can be effective and could be used to replace the PbBi solder commonly used with the superconducting properties Tc = 8.4K, HC2 = 1.77 T, HC = 0.0909 T.

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“…As estimated by us, the joint resistance should be lower than 10 −17 Ω to obtain a drift rate of less than 1 µgal yr −1 , which can reach the investigation criteria. However, based on the experience of using the NbTi superconducting joint, most of the joint resistance, either from the cold pressing method or the matrix replacement method, is approximately 10 −14 Ω, which is significantly different from the criterion [5][6][7][8].…”

Section: Introductionmentioning

confidence: 99%

A novel Nb superconducting joint with ultralow resistance fabricated by electron beam welding method for superconducting gravimeter

Zhang

Xing

Cui

et al. 2021

Supercond. Sci. Technol.

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This paper presents a novel Nb superconducting joint with an ultralow resistance of 7.9 × 10−16 Ω, fabricated using the electron beam welding (EBW) method. After the EBW process, the two Nb filaments formed a single joint with a much larger grain size and smaller grain misorientation. More importantly, the resistance of the EBW Nb joint was nearly one magnitude lower than that of most conventional pressing joint. The ultralow resistance is essential for superconducting gravimeters, which require an extremely low drift rate. The EBW Nb joint allowed the superconducting gravimeter to have a much better performance when applied in the field of structural geology, geodesy, microgravity, and metrology. We believe that the EBW method could be one of the most promising joint fabrication methods for achieving maximum stability (less than 1 μgal yr−1).

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The effect of the size of NbTi filaments on interfacial reactions and the properties of InSn-based superconducting solder joints

Cited by 22 publications

References 47 publications

Nucleation and Morphology of Cu6Sn5 Intermetallic at the Interface between Molten Sn-0.7Cu-0.2Cr Solder and Cu Substrate

Nucleation and Morphology of Cu6Sn5 Intermetallic at the Interface between Molten Sn-0.7Cu-0.2Cr Solder and Cu Substrate

Demonstration of better superconducting performance in a solder with low lead content

A novel Nb superconducting joint with ultralow resistance fabricated by electron beam welding method for superconducting gravimeter

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