Advanced alloy superconductor wire manufacturing technology. Fnal technical report on phase 1

Researchers have developed a new manufacturing route for the preparation of multifilamentary wires which could lead to the production of higher performance superconductor wires at significantly lower cost. Continuous filaments of superconductor alloy wires have been prepared directly from the melt, employing an advanced rapid solidification technology. The rapidly solidified filaments were typically 40 micrometers thick and 0.5 mm wide. The high solidification rates experienced by the thin filaments resulted in fine grain sizes and a chemically homogeneous microstructure. The critical current density of rapidly solidified Nb-46.5 w% Ti alloy was considerably improved by either the generation of fine boride precipitates dispersed uniformly within the matrix, through rapid solidification processing, or by annealing treatments to create titanium rich precipitates within the matrix. The matrix of rapidly solidified Nb-Ti alloy was relatively free of sub-structure. The required sub-structure can be generated by mechanical deformation during the wire drawing step, which will be required to produce multifilamentary composite superconductor wires