The possible dominant factors in the mechanical properties of the metallic substrates of various commercial REBCO tapes

The metallic substrate of commercial REBCO tapes from eight different manufacturers has been systematically investigated. Tensile properties at both room temperature and 77 K were measured. The grain morphology, size, orientation, dislocation density, and internal stress of the grains on both the cross-section and surface of each tape were studied using EBSD. After an in-depth analysis of the relationship between yield strength and grain size, elemental composition, dislocation density, and twin boundaries, it has been preliminarily confirmed that dislocation density is a possible dominant factor in determining the yield strength of the metallic substrate of commercial REBCO tapes.The kernel average misorientation value (KAM) of the cross-section could be one of the best indicators for evaluating yield strength. Based on this analysis, potential methods for enhancing yield strength are also briefly discussed. This investigation aims to provide valuable insights for researchers to better understand the mechanical properties of REBCO tape.