The fabrication of silver-sheathed Y(Ba,K)2Cu3O7 superconducting rods by explosive compaction and subsequent warm-plastic deformation, employing multiple-pass extrusion at 470°C, is reported and discussed. The impurity phase content, as well as the superconductivity of the component, were carefully controlled by employing intermediate and post-processing heat-treatment in flowing oxygen. The characterization of the extruded rod, after every extrusion pass, indicates a progressive microstructural refinement, leading to subsequent reduction of the porosity, closing of microcracks and enhancing the integrity of the metal/ceramic interface. Evaluation of the mechanical properties of the ceramic core-material, e.g. microhardness and fracture toughness, indicated significant improvement of the formability of the fabricated component. The various phase-transformations and transition temperature, Tc changes are presented and discussed, with respect to the manufacturing processes employed. Extruded rods, of 5 mm diameter and 50 mm length, are used as HTS conductors in a rotating electrical machine.
ASJC Scopus subject areas
- Physics and Astronomy(all)