Mechanical Properties of Non-Superconducting Components in YBCO and Nb3Sn Composites

Non-superconducting materials are essential components in both YBCO and Nb3Sn composites for magnet applications. The surface of the composites is made of pure Cu that is referred as stabilizer. The surface finish is very important for the applications, particularly in the case where thin layers of insulations are required. The stabilizer usually occupies 50% to 70% of the volume fraction of the composites, thus making an important contribution to the mechanical properties of the composites. The other components, such as Cu-Sn matrix in Nb3Sn conductors and substrates in YBCO conductors also contribute to overall mechanical strength. Therefore, understanding the performance of the non-superconducting components under loading helps engineers to make effective use of the superconductor composites and to manufacture conductors meeting the requirements of the magnets, particularly when the magnetic stress reaches the limit of the mechanical strength of the conductors. This paper compares the mechanical properties of YBCO and Nb3Sn composites and discusses the mechanical properties of non-superconducting components in both composite conductors and to relate such properties to dislocation densities and various boundaries. This paper also relates the mechanical properties to other microstructure parameters.