Mechanical properties of ZrCuTi thin film metallic glass with high content of immiscible tantalum

Abstract

The ZrCuTi thin film metallic glasses (TFMGs) with immiscible Ta were successfully fabricated via co-sputtering. The glass forming composition for ZrCuTi–Ta TFMGs ranges from 0 to ~ 75 at.% of immiscible Ta, distinctly different from bulk metallic glasses (BMGs). When Ta content is over 75 at.%, the amorphous TFMG structure gradually transforms to nanocrystalline β-Ta. The mechanical properties are strongly influenced by Ta content. The elastic modulus remains nearly constant over 0–50 at.% Ta, and increase rapidly over 50–100% Ta. The key factor appears to be the population of the Ta–Ta strong bonds. The highest elastic modulus and hardness up to ~ 140 GPa and 10 GPa, respectively, of the Ta-rich TFMGs, much higher than the Zr-, Cu- and Ti-based amorphous alloys, might be useful for applications.