Achieving pronounced β-relaxations and improved plasticity in CuZr metallic glass

Johari-Goldstein secondary relaxation known as β-relaxation has long been considered to play a key role in mechanical behaviors of metallic glasses (MGs). CuZr alloys are typical MG system exhibits non-pronounced β-relaxation and poor ductility. In the present work, we showed that pronounced β-relaxation that only observed in few La- and Y-based MG systems could be achieved in Cu₅₀Zr₅₀ MG and effectively improve the plasticity of the CuZr alloys. Other than the well-documented strain-like motions, the simulation results and analysis indicated, higher degree heterogeneity generated in severe deformed region is responsible to the unusual pronounced β-relaxation. The outcomes of current work not only deepen understanding of the microstructural origin of β-relaxation, also path a new way to alter the β-relaxation and plastic deformation behaviors of MGs.