Role of high pressure treatments on the atomic structure of cuzr metallic glasses

Thermal-pressure treatments for metallic glasses (MGs) rejuvenation involve large pressures up to tens of gigapascals. Such conditions can lead to structural changes beyond pure energy excitation that have not been fully explained in the literature. In this work, molecular dynamics simulations were employed to inspect the relationship between pressure treatments and structural properties in CuZr MGs. To this aim, hydrostatic pressure tests up to 70 GPa were performed at constant temperature and several physical parameters were calculated before and after the tests. Significant structural changes were identified at pressures above 50 GPa, leading to higher energy states, increased atomic volume, and larger populations of high centrosymmetric Voronoi polyhedra. Network analysis revealed that the degree of bond connectivity between such polyhedra decreased drastically, reducing their packing efficiency and weakening the structural backbone of the material. Overall, these results provide new insights into structural behaviors previously observed during CuZr MGs rejuvenation at large pressures.