Mechanical and superconducting properties in Bi-2223 bulks for current lead

摘要

In order to apply oxide superconductors for current leads, it is very important to invesigate the mechanical properties. We measured the bending strength of Bi-2223 bulks fabricated by the cold isotatic pressing technique. The flexural strength( sigma _(bmax) depended on the sintering temperatures, but it was independent of the critical current density (Jc). The sigma _(bmax) of 55 approx MPa and 40 approx 50 MPa were obtained for rod and pipe specimens which had the maximum critical current, respectively. These results indicated that have the strength enough to tolarate the Lorenz force when we apply the Bi-2223 bulks for current leads in superconducting magnet systems. Moreover, no change in J_c and contac resistance (R_c) characteristics were observed below a stress of less than sigma _(bmax).