Size-dependent mechanical responses of metallic glasses

ABSTRACT Metallic glasses (MGs) are arguably one of the most exciting metallic systems in the past 30 years, attracting significant research effort and undergoing rapid development. Parallel to research on crystalline metals, the sample size has been exploited as property-tuning parameters for MGs. It has been shown that nanometre-sized MG samples exhibit higher-than-bulk elastic limit, tensile strength, and non-zero tensile ductility. While some of the size-related observations have been generally accepted, others have been poorly understood, even hotly debated. Of particular interests is the importance of sample preparation in experiments and model generation in simulations. Here, we will review how the sample size affects mechanical properties including the elastic, plastic, fracture properties, and fatigue endurance, as well as various proposed size-dependent mechanisms and relevant length scales.