The influence of deformation on the medium-range order of a Zr-based bulk metallic glass characterized by variable resolution fluctuation electron microscopy

Hilke Sven, Rösner Harald, Geissler David, Gebert Annett, Peterlechner Martin, Wilde Gerhard

Zusammenfassung

The medium-range order (MRO) of both as-cast and deformed states of a Zr-based bulk metallic glass (Zr52.5 Cu17.9 Ni14.6 Al10 Ti5 (at.-%) - Vitreloy 105) were analyzed using variable resolution fluctuation electron microscopy (VR-FEM). After deformation significant structural changes in the MRO were observedsigni inside the shear bands and the adjacent matrix; the MRO was altered in terms of types, size and volume fractions. The changes in the matrix MRO cofirmn the existence of a shear affected zone around the shear band in our deformed sample. Since the MRO correlation length was larger inside the shear bands compared to the surrounding matrix, it is concluded that either frictional heat dissipation or shear induced nucleation and growth also plays a role in the alteration of MRO. The current work illustrates the significance of MRO in deformation of metallic glasses and suggests that the plasticity of monlithic BMGs can be improved by tailoring topological order based on MRO types, sizes and volume fractions.