Properties of Ag–Mg alloy sheathed Bi-2223 tapes Original Research Article

The mechanical properties of 37 filament, pure Ag and Ag alloy (0.2 and 0.5 wt% Mg) sheathed Bi-2223 high temperature superconductor tapes were investigated. The use of Ag–Mg alloys enabled strengthening of the sheaths by an oxide dispersion strengthening (ODS) mechanism. The sheath hardness, tape tensile strength and the tolerance of the superconducting critical current to bending and axial strains increased with the concentration of the alloy addition. The sheath hardness results revealed evidence of overaging. Excessive hardening of the sheath, however, lead to the formation of rolling defects during the intermediate deformation stage of tape processing.