Effect of heat treatment on the structure and mechanical properties of the semi-finished products from NbTa(Zr,Hf,Y) alloy for the manufacture of Nb3Sn superconductors

The influence of the degree of deformation and annealing on the mechanical properties of Nb-based alloy samples of different compositions: Nb-Ta-Zr, Nb-Ta-Hf, Nb-Ta-Zr-Y used in the manufacture of Nb3Sn superconductors is studied. The deformability of Nb-based alloys in the composition of single-fiber composite Nb3Sn superconductors, which were manufactured using the technology of an internal tin source and the «powder – in – tube» method, has been studied. It is shown that the values of the time resistance of samples with a sheath made of Nb alloys 7.5 wt.% Ta–0.5 wt.% Zr and Nb–7.5 wt.% Ta–1 wt. % Zr are at the same level of ~ 650 MPa, and the elongation values are ~ 2%. The structural features of the fracture surface of Nb-based alloy samples with varying degrees of accumulated deformation and single-fiber conductors have been studied. The results of the work will be used in the development of technological modes for manufacturing Nb3Sn-based superconductors.