Importance of Composite Design for the Microstructure of Bundle Drawned Multifilamentary Nb3Sn Wires

Abstract

Composites made of niobium filaments within an oversaturated α-CuSn bronze matrix were processed by restack bundle drawing. The differences in mechanical behaviour of the various components entail an heterogeneity of deformation. Such a feature is mostly unfavourable not only for the phase transformations that govern the microstructure and the electromagnetic properties but also for the composite mechanical integrity. The obtained results finally demonstrate the chief importance of the selection of both the design of the composite and the processing steps.