Fracture of brittle filaments plays a crucial role in significant degradation of critical current density of multifilamentary Nb₃Sn strand. Recent researches of distribution of filament factures mostly depend on photographic analysis with SEM or TEM. However, it is hard to obtain spatial distribution of filament fractures in the mulitifilamentary Nb₃Sn strand. In addition, almost unavoidable filament fracture is introduced during the sample preparation procedure and it causes deviation of filament fracture distribution. X-ray microtomography is a non-invasive, non-destructive method, which allows determination and the discrimination of internal features without destructing the sample. It is widely used as a non-destructive test technology for its high penetrability and high resolution. This present work investigated filament fracture of two types of Nb₃Sn strands under different tensile strains by high energy X-ray. The influence of tensile strain on the filament fracture behavior was investigated and the results will be expected to provide reference for optimization of multifilamentary Nb₃Sn strand, conductor and magnet design.

脆性长丝的断裂在复丝Nb ₃ Sn股的临界电流密度的显着降低中起关键作用。细丝断裂分布的最新研究主要依赖于用SEM或TEM进行的照片分析。但是，在多丝Nb ₃中难以获得长丝断裂的空间分布。锡线。另外，在样品制备过程中几乎不可避免地引入了细丝断裂，这导致细丝断裂分布的偏差。X射线显微断层照相术是一种非侵入性，非破坏性的方法，可以在不破坏样品的情况下确定和辨别内部特征。它以其高穿透性和高分辨率而被广泛用作无损检测技术。本工作通过高能X射线研究了两种Nb ₃ Sn股线在不同拉伸应变下的细丝断裂。研究了拉伸应变对细丝断裂行为的影响，该结果有望为优化多丝Nb ₃ Sn钢绞线，导体和磁体设计提供参考。