Effect of Cu Edges on Delamination Strength in Cu-Stabilized CC Tapes Under Transverse Tension at 77 K

Delamination frequently occurs as a result of high transverse tensile stresses caused by fabrication and mechanical and thermal cycles during operation. It is generally known that transverse opening and peeling off are the primary delamination failure modes, and delamination strength is typically evaluated using anvil or peel tests. To avoid transverse openings that cause delamination failures in coated conductor (CC) tapes, the tape structure can be changed by developing or adding the fabrication process. Thus, in most studies, delamination strength has been characterized in REBCO CC tapes with Cu-edges and the slit-side one. In this study, the delamination strengths of 12-mm-wide CC tapes without a slit edge and a 4-mm-wide CC tapes without Cu-edges were experimentally measured under transverse tensile loading at 77 K. Results were compared to those obtained during the mechanical delamination of CC tapes with Cu edges. The delamination morphologies were also observed macroscopically.