The effects of glass–glass interfaces on thermodynamic and mechanical properties of Co–Fe–P metallic nano-glasses

Pulse electrodeposition is utilized to prepare Co–Fe–P metallic nano-glasses (NGs) containing glassy grains with an average size D < 100 nm. The effects of glass–glass interfaces (GGIs) on thermodynamic and mechanical properties of NGs are systematically studied. The glass transitions in NGs as characterized by differential scanning calorimetry and dynamic mechanical analysis show that they are strongly affected by D or the volume fraction of GGIs. In comparison with those for conventional metallic glasses, a predominant internal-friction peak corresponding to the glass transition is observed for NGs with reduced D, suggesting that the GGIs are in a glassy state much different with that of glassy grains in NGs. Nanoindentation measurements on the hardness and volume of shear transformation zones reveal that the GGIs could accommodate plastic strains in NGs, where homogeneous plastic deformation occurs. Graphical abstract: [Figure not available: see fulltext.].