The Introduction of Titanium into Internal-Tin rm Nb₃rm Sn by a Variety of Procedures

The advantages of titanium as a third element in Nb/sub 3/Sn have been known for many years. It increases the upper critical field and lowers the critical current density at lower fields, thus reducing the losses, which are usually measured in this field region. Several methods for the introduction of titanium are listed and discussed briefly. The two methods discussed in more detail are both introduction by way of Nb47wt.%Ti. One is by wrapping foils around the filaments and the other by introducing rods into the filament array. A relatively uniform distribution of Ti in the filaments, results from both methods. Scanning Electron Microscopy (SEM) was used to illustrate the various phases, produced under different heat treatment conditions. Energy Dispersive Spectroscopy, (EDS) and Wavelength Dispersive Spectroscopy, (WDS) were both used to obtain compositional data.