Production of a Large Diameter High-Current Nb-Ti Wire
Transmission electron microscopy was used to study the phase transformation kinetics of Nb-48Ti alloy after variable degrees of plastic deformation had been wrought on the alloy during its production. On the basis of the structural studies the optimized conditions of various treatments were chosen such as to firmly secure the increased current-carrying capacity of a large-size multifilamentary superconductor. Thus, in case of a 210-filament superconductor 1.6mm in diameter the value Ic(5 T) was as high as 2700 A with jc(5 T) being 2.85 109A/m2 (2.85 105 A/cm2), accordingly. Mechanical characteristics of the produced superconductors were measured.
KeywordsCritical Current Density Deformation Space Phase Transformation Kinetic Ingot Diameter Heterophase Structure
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