Universal mechanism of thermomechanical deformation in metallic glasses

We investigated the atomistic structure of metallic glasses subjected to thermomechanical creep deformation using high energy x-ray diffraction and molecular dynamics simulation. The experiments were performed in situ at high temperatures as a time dependent deformation in the elastic regime, and ex situ on samples quenched under stress. We show that all the anisotropic structure functions of the samples that have undergone thermomechanical creep can be scaled into a single curve, regardless of the magnitude of anelastic strain, stress level, and the sign of the stress, demonstrating universal behavior and pointing to a unique atomistic unit of anelastic deformation. The structural changes due to creep are strongly localized within the second nearest neighbors, involving only a small group of atoms.