We measured the atomic-scale elastic strain in order to investigate the yielding of ${\mathrm{Zr}}_{55}{\mathrm{Cu}}_{20}{\mathrm{Ni}}_{10}{\mathrm{Al}}_{10}{\mathrm{Ti}}_5$ and ${\mathrm{Cu}}_{47.5}{\mathrm{Zr}}_{47.5}{\mathrm{Al}}_5$ bulk metallic glasses (BMGs) by x-ray synchrotron radiation at room temperature. High resolution strain scanning reveals a deviation from the linear stress-strain relationship at the onset of macroplastic flow. Similar to polycrystalline metals, a saturation of the elastic strain components has been revealed in the case of the “plastic” ${\mathrm{Cu}}_{47.5}{\mathrm{Zr}}_{47.5}{\mathrm{Al}}_5$ BMG. The results show that the atomic-level elastic strains of the plastic ${\mathrm{Cu}}_{47.5}{\mathrm{Zr}}_{47.5}{\mathrm{Al}}_5$ BMG are more homogeneous compared to the “brittle” ${\mathrm{Zr}}_{55}{\mathrm{Cu}}_{20}{\mathrm{Ni}}_{10}{\mathrm{Al}}_{10}{\mathrm{Ti}}_5$ glass.

• Received 21 August 2007

DOI:https://doi.org/10.1103/PhysRevB.76.092203