Low temperature mechanical properties of Y123 bulk superconductor fabricated by the modified QMG process

The monotonic and the repeated bending tests on the Y123 single grain bulk superconductor sample were carried out. The average Young's modulus at liquid nitrogen temperature (LNT), 148 GPa, was higher than that at room temperature (RT), 132 GPa. The average bending strength at LNT, 90 MPa, was also higher than that at RT, 74 MPa. The Weibull coefficient for the bending strength at RT, 17.6, was significantly larger than that at LNT, 6.1. The specimen cut from the bottom region of the bulk superconductor showed slightly higher value of the Young's modulus and lower value of the bending strength. The fatigue endurance limit for the repeated pulsating loading up to 5 x 10(4) cycles at LNT, 70 MPa, was about 80% of the bending strength. (C) 2004 Elsevier B.V. All rights reserved.