Metallic Nanoglasses with Promoted β-Relaxation and Tensile Plasticity

The secondary (beta) relaxation is an intrinsic feature of glassy systems and is crucial for the mechanical properties of metallic glasses. However, it remains puzzling what structural features control the beta-relaxation fundamentally. Here, we use the recently developed nanoglasses exhibiting well-defined structural features at the nanometer scale to interrogate such structure-dynamics relations. We show that an electrodeposited Ni77.5P22.5 nanoglass exhibits promoted beta-relaxation and enhanced microscale tensile plasticity over the most rapidly melt-quenched metallic glass with the same composition. Structurally, the beta-relaxation is sensitive to the interfacial regions among grains in the nanoglasses. Our results reveal a clear correlation between the amorphous nanostructures and the beta-relaxation. It seems that the nanostructuring represents a novel route to obtain high-energy glassy states, that is, the inverse problem of the ultrastable glass.

Automated summary

Nanoglasses exhibit promoted beta-relaxation and enhanced microscale tensile plasticity compared to rapidly melt-quenched metallic glasses. The beta-relaxation is sensitive to the interfacial regions among grains in nanoglasses, showing a clear correlation between amorphous nanostructures and the beta-relaxation.