Room-temperature impact-induced damage and electromagnetic property degradation of Nb 3 Sn wires

Abstract The intrinsic brittleness of Nb₃Sn wires render them highly sensitive to mechanical loading, yet the effects of room-temperature impact loading on their structural and electromagnetic properties remain underexplored. In this study, Nb₃Sn wires were subjected to controlled impact loads using a Hopkinson bar apparatus, and their damage was evaluated via scanning electron microscopy combined with a home-made crack identification algorithm. The results reveal the progressive formation of X-shaped damage zones with increasing impact intensity, predominantly in the central region of the wire; the observed degradation correlates directly with the severity of mechanical impact. Magnetization measurements conducted using a physical property measurement system reveal that the flux jump frequency of Nb₃Sn wires increases gradually with the application of impact. This upward trend persists until the wires undergo failure, after which the flux jumps frequency decreases. Concurrently, the critical current density of the wires degrades severely, the flux pinning force drops significantly, and their overall electromagnetic performance deteriorates substantially. These findings provide key insights into the damage tolerance of Nb₃Sn conductors and inform the design of impact-resistant superconducting magnets.