THE EFFECT OF BENDING RADIUS ON V-I CHARACTERISTICS OF MONOCORED 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 sam e specimen. The critical current Ic and shape of high-sensitivity VCC as a function of bending strain are analysed. Degradation of current c arrying 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 sheat h and to appearance of linear resistance segment in the V-I curve at l ow electric field.