Mechanical failure: A critical bottleneck for high-field high-temperature superconducting magnets

The pursuit of ultrahigh-field high-temperature superconducting (HTS) magnets faces a significant challenge: mechanical failure is a primary fundamental limiter of progress. In extreme cryogenic electromechanical environments, coupled multimode failures—namely interfacial delamination, intralayer fracture, substrate yielding, and buckling—form the critical bottleneck. These failure modes are intrinsically coupled: Lorentz forces generate destructive hoop stresses, thermal expansion coefficient mismatches induce radial interface-decoupling tensions, multiaxial stress states accelerate crack propagation, and cyclic loads cause irreversible performance degradation. Such mechanical failures typically precede quench events. The resolution of these issues demands convergent innovation integrating material-centric strategies, structural intelligence, and operational resilience. Overcoming this mechanical barrier is pivotal for incremental field gains and unleashing the transformative potential of HTS magnets in fusion energy, next-generation nuclear magnetic resonance, and compact medical devices. A cross-disciplinary paradigm fusing materials science, solid mechanics, and intelligent engineering is necessary to transcend this frontier.