Numerical investigation of residual stresses in YBCO/CeO ₂/YSZ/CeO₂/Ni architextured materials for coated conductors

In this study, the stress analysis of YBCO/CeO₂/YSZ/CeO ₂/Ni architextured materials under cryogenic conditions was carried out for coated conductor applications. YBCO/CeO₂/YSZ/CeO₂ multilayer films were fabricated on Ni tape substrate using reel-to-reel sol-gel and Pulse Laser Deposition (PLD) systems. The microstructural evolution of high temperature superconducting YBCO film and buffer layers with CeO ₂/YSZ/CeO₂ configuration grown on textured Ni tape substrates were investigated by a Scanning Electron Microscope (SEM). SEM observations revealed that crack-free, pinhole-free, continuous superconducting film and buffer layers were obtained by solgel and PLD systems. The thermal distribution in the each layer was calculated using the classical lamination theory in the temperature range of 25 to-270°C in liquid helium media. The residual stresses occurred during the manufacturing are neglected therefore, all the residual stresses are assumed to be zero at 25°C. Different thermal expansion coefficients and modulus of elasticity bring about the thermal stresses in the layers.