The transverse stress effect on the critical current of jelly-roll multifilamentary Nb3Al wires

Experiments were conducted to determine the effect of transverse compressive stress (TCS) on the critical current of jelly-roll multifilamentary Nb₃Al wire (0.8-mm dia.) for magnetic flux densities up to 12 T. For comparison, identical experiments were performed for bronze-process Ti-alloyed multifilamentary Nb₃Sn wire (1.0-mm dia.). Although the unstressed critical current density of Nb₃Al was inferior to that of (NbTi)₃ Sn at high fields, under applied TCS Nb₃Al exhibited less critical current degradation than (NbTi)₃Sn. For example, at 12 T and 150 MPa. TCS-induced critical current degradation was approximately 20% for Nb₃Al, whereas it was approximately 65% for (NbTi)₃Sn