A Nanoglass-Crystalline TbFe Composite with Exceptional Tensile Ductility

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 Tb₈₀Fe₂₀ phase dispersed in a nanoglass Tb₅₀Fe₅₀ 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.