A Nanoglass‐Crystalline TbFe Composite with Exceptional Tensile Ductility

Abstract Nanostructured alloys and metallic glasses (MGs) typically exhibit low tensile ductility, while composite nanostructures with intermetallics improve mechanical performance mainly under compression. A composite nanostructure is reported here achieved via a single‐step melt spinning process with a non‐equilibrium ductile crystalline Tb ₈₀ Fe ₂₀ phase dispersed in a nanoglass Tb ₅₀ Fe ₅₀ matrix. The high density of nano‐amplitude pop‐in events evidenced during nanoindentation tests strengthened the proposition that heterogeneous interfaces discretize the shear banding in 3D nanoglass matrix – a key mechanism to improve ductility of MGs. Consequently, the nanoglass‐crystalline composite achieved a tensile plasticity of ≈22% and a total elongation to failure of ∼39%. These findings confirm the potential for designing highly ductile nanostructured materials, essential for advanced structural applications.