The effect of bending radius on V-I characteristics of mono- and multicored BiPb-2223 tapes with and without Ag additions

The effect of bending strain on Voltage-Current Characteristics (VCC) of BiPbSrCaCuO-2223/(Ag and Ag-alloy sheathed) tapes with and without Ag additions into the core have been studied. The testing probe allows us to carry out all set of bending tests up to radius 5 mm on the same specimen. The critical current Ic and shape of high-sensitivity VCC as a function of bending strain are analysed. Degradation of current carrying capacity under bending deformation is caused by the formation of microcracks. The overlapping of microcracks in Bi-2223/Ag sheathed tapes without Ag additions leads to current overflow into the Ag sheath and to appearance of linear resistance segment in the V-I curve at low electric field.