Effect of modulation ratio on the mechanical behavior of multilayer-thin-film metallic glasses

Abstract

This study investigates the effect of modulation ratio on the mechanical characteristics of multilayer zirconium-based thin film metallic glasses (Zr-based TFMG) by nanoindentation and finite element (FE) method. Multilayer TFMGs (Zr–Cu–Al–Ni and Zr–Cu–Ag) with different modulation ratio (λ = thickness of layer 1/layer 2) are deposited on silicon (Si) wafer substrates by magnetron sputtering. The load-depth responses of TFMGs to nanoindentation are observed in both experiments and FE simulations, in which pressure dependent free-volume-model (FVM) is employed for TFMGs. The changes in mechanical behavior with film thickness, layer pattern, modulation ratio and indentation depth are compared between single and multilayer TFMGs. It is demonstrated that an appropriate selection of layer pattern and modulation ratio can improve the mechanical performance of multilayer TFMG systems. The proposed FE model can be utilized for tailoring multilayer thin film deposition for achieving maximum mechanical performance of TFMG coated products.