Tuning the Physical Properties of V-Ti-Ce Alloy Superconductors Through Successive Cold-Working and Annealing at 650 °C

Abstract V- Ti alloys are promising alternatives to Nb for the construction of superconducting solenoids that produce high magnetic fields. The critical current density ( $$J_C$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>J</mml:mi> <mml:mi>C</mml:mi> </mml:msub> </mml:math> ), which quantifies the capacity of a superconductor to carry large dissipationless current, increases in the V-Ti alloys with the addition of Ce. Here, the effects of successive cold working and annealing on the electrical resistivity, $$J_C$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>J</mml:mi> <mml:mi>C</mml:mi> </mml:msub> </mml:math> , and microstructure of the V $$_{0.59}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow> <mml:mn>0.59</mml:mn> </mml:mrow> <mml:mrow/> </mml:mmultiscripts> </mml:math> Ti $$_{0.40}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow> <mml:mn>0.40</mml:mn> </mml:mrow> <mml:mrow/> </mml:mmultiscripts> </mml:math> Ce $$_{0.01}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow> <mml:mn>0.01</mml:mn> </mml:mrow> <mml:mrow/> </mml:mmultiscripts> </mml:math> alloy are studied. The $$J_C$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>J</mml:mi> <mml:mi>C</mml:mi> </mml:msub> </mml:math> is the maximum after the second cold rolling. Annealing at 650 $$^{\circ }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mmultiscripts> <mml:mrow/> <mml:mrow/> <mml:mo>∘</mml:mo> </mml:mmultiscripts> </mml:math> C is found to nucleate and grow the $$\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> -phase which is detrimental to $$J_C$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>J</mml:mi> <mml:mi>C</mml:mi> </mml:msub> </mml:math> , whereas the precipitation of the $$\alpha '$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mi>α</mml:mi> <mml:mo>′</mml:mo> </mml:msup> </mml:math> -phase is found to improve the $$J_C$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>J</mml:mi> <mml:mi>C</mml:mi> </mml:msub> </mml:math> .