An improved method for fabrication of Nb3(Al,Ge) wire

Technologies for fabrication of Nb3(Al.75Ge.25) wire by reaction of mechanically fabricated composites of Nb, Al and Ge have had very limited success due to the lack of plasticity of elemental Ge, which leads to gross compositional inhomogeneity and low transition temperatures. However, it is possible to develop considerable ductility in Al-Ge alloys, and by using such alloys composited with Nb, composites may be mechanically fabricated which, when reacted in wire form, have transition temperatures ca. 20°K. Due to the nature of the ternary phase diagram, such transition temperatures may be achieved for all core compositions between Al- 14% Ge and Al-30% Ge. However, high reaction temperatures, ca. 1800°C, are necessary, which suggests low-temperature stability problems with the A15 phase which are similar to those in the binary Nb-Al system.