Binary Cu-Zr thin film metallic glasses with tunable nanoscale structures and properties

Abstract

In the present work, we develop a series of binary Cu-Zr thin film metallic glasses (TFMGs) with tunable nanoscale structures by using direct-current (DC) magnetron sputtering technique. Depending on the chemical composition and the sputtering parameters, Cu-Zr TFMGs show variable nanoscale structures from nanocolumn to nanogranula. As compared to the metallic glassy ribbons with identical composition, the Cu-Zr TFMGs with nanoscale structures exhibit novel and unique thermal and mechanical properties. From nanoindentation study, it is found that the TFMGs with nanoscale structures display obvious reduced hardness (about 48–52%) and increased elastic modulus (about 7–23.8%) as compared to the metallic glassy ribbons. Moreover, the serrated flow behavior, as commonly observed from the load-displacement response in the nanoindentation of metallic glasses (MGs) is absence for nanostructured TFMGs, indicating the profound effects of nanoscale structural features on the plastic yielding and flow in TFMGs. This study provides a detail insight into a strategy of designing nanostructured TFMGs and obtaining tunable properties which is of great interest in the potential application of micro/nanoscale devices.