Preparation of Bi-2223 bulk composed with silver-alloy wire

Abstract

Abstract We prepared Bi-2223 sintered bulk composed with silver alloy wires to improve simultaneously both the superconductivity and the mechanical properties. When 24 Ag alloy-wires of 0.4 mm in diameter were composed, the critical current density ( J c ) at 77.3 K in the self-field was obtained 700 A/cm 2 . Scanning electron microscope observation results showed that dense structure of Bi-2223 plate-like grains was formed around the interfacial region between the Bi-2223 oxide and metal Ag. The mechanical property was estimated by three point bending test. The bending stress of 80 MPa at the rupture was obtained for Bi-2223 AgMg alloy composite bulk irrespective of the number of the wires. In the AgZr alloy-wires composite bulks, the bending stress decreased to the half value of that in Bi-2223 bulk without the wires. After the maximum bending stress the sample fractured separately in Bi-2223 bulk without alloy-wires, while the composite did not fracture but only fine cracks were induced.