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Influence of Ti and Ta doping on the irreversible strain limit of ternary Nb3Sn superconducting wires made by the restacked-rod process



Najib Cheggour, Loren F. Goodrich, Theodore C. Stauffer, Jolene D. Splett, Xifeng Lu, A. K. Ghosh, G. Ambrosio


Nb3Sn superconducting wires made with restacked-rod process (RRP®) were found to have a dramatically improved resilience to axial tensile strain when alloyed with Ti as compared to Ta. Whereas Ta-alloyed Nb3Sn in RRP wires showed permanent damage to its current-carrying capacity (Ic) when tensioned beyond an intrinsic strain as small as 0.04 %, Ti-doped Nb3Sn in RRP strands exhibit a remarkable reversibility up to a tensile strain of about 0.25 %, thus making Ti-doped RRP wires more suitable for high-field magnets used in particle accelerators and nuclear magnetic resonance applications where mechanical forces are intense. A strain cycling experiment at room temperature caused a significant drop of Ic in Ta-alloyed wires, but induced an increase of Ic in the case of Ti-doped strands. Whereas either Ti or Ta doping yields a similar enhancement of the upper critical field of Nb3Sn, the much improved mechanical behavior of Ti-alloyed wires clearly makes Ti a better choice over Ta, at least for the RRP wire processing technique.
Superconductor Science and Technology


Superconductors, Ternary Nb<sub>3</sub>Sn, Alloys, Strain, Irreversible Strain Limit, Strain Cycling, Fracture


Cheggour, N. , Goodrich, L. , Stauffer, T. , Splett, J. , Lu, X. , Ghosh, A. and Ambrosio, G. (2010), Influence of Ti and Ta doping on the irreversible strain limit of ternary Nb<sub>3</sub>Sn superconducting wires made by the restacked-rod process, Superconductor Science and Technology, [online], (Accessed May 18, 2024)


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Created April 1, 2010, Updated February 19, 2017