ABSTRACT
This chapter focuses on the fabrication techniques which is used to produce high-current-density wire. When trying to gain an understanding of the metallurgy of an alloy, the first step is to examine the phase diagram. The processing required to optimize the microstructure will change with composition. Higher-Ti alloys are more susceptible to the formation of the metastable ω-phase, as the BCC Nb lattice is softened by Ti addition. Since the trial-and-error approach requires a great deal of time and money, manufacturers were reluctant to stray from a successful alloy and processing combination. The chapter also focuses on Cu-Nb-Ti composites, with reference to other combinations where applicable. Copper surfaces quickly oxidize and so are etched immediately prior to billet assembly. The hard intermetallic agglomerates and induces filament sausaging during further drawing. Multifilamentary superconducting wire is, on the other hand, much more stable than tape, especially for application in time-varying fields.
