Strain aging in metallic glasses

Abstract

We investigate the evolution of strain and viscosity in metallic glasses during the cyclic tensile creep experiments at a constant temperature. The effects of cyclic creep result in increasing viscosity and structural relaxation, which are attributed to the shrinkage and annihilation of flow units. We further confirm the strain deformation effect via β-relaxation and relaxation enthalpy measurements. We find that the strain deformation also has the dramatic negative effect on the β-relaxation behavior and relaxation enthalpy of metallic glass, and leads to an aging phenomenon. The results indicate that the deformation accelerate the structural relaxation which is closely correlated with the inhomogeneous microstructure and the potential defects of flow units in metallic glasses.