A number of materials lose their electric resistance at low temperatures – they become superconductive.
One of the metallic alloys which has become commercially important is Nb 3Sn. Wires made of this alloy are used for the production of high field strength magnets, for example in nuclear magnetic resonance spectroscopy.
During the production of superconductive multi-filamentary Nb 3Sn wires according to the bronze method, copper-tin billets are extruded and then, together with niobium rods, co-extruded, drawn and finally annealed to form the superconductive Nb 3Sn phase.
Spray-formed high tin bronzes have many advantages which are beneficial to the production of superconductive Nb 3Sn wire. The microstructure of spray-formed bronze billets is fine-grained with significantly reduced microsegregation. Homogeneous intermetallic phase distribution allows the elimination of the initial heat treatment and increases overall process stability during further hot and cold working.
