Room temperature dynamic indentation response of partially crystallized Zr–Cu metallic glass

Exciting a metallic glass with a small oscillatory perturbation can yield significant insights into the atomistic mechanisms governing relaxation phenomenon. Dynamic mechanical analysis (DMA) is a versatile tool to study the structural relaxation of amorphous materials that exhibit prominent peaks in loss modulus as a function of temperature. In this work, room temperature dynamic indentation was performed on Zr67Cu33 MG ribbon at 1 and 2 mN loads. Small oscillatory loads of 50 and 75 μN have been superimposed on the applied loads during a frequency sweep experiment (10–160 Hz). The results indicate that the loss modulus is independent of the frequency for this sample in the tested range. When the as cast MG ribbon was characterized through high resolution transmission electron microscopy (HRTEM), it revealed the presence of nanocrystals with a diverse crystallographic nature. The frequency independent dynamic response in this study is ascribed to the damping of oscillatory load by the nanocrystals. •Presence of nanocrystals in metallic glass can dampen the evolution of flow units.•Large variations in the dynamic mechanical properties observed at certain frequencies.•Dynamic indentation response of partially crystallized MG is different from monolithic MGs.