Effect of sample size and cooling rate on the plastic deformation behavior of bulk metallic glasses: A comparative study

Abstract

Understanding the differences between the cooling-rate and size effects on the plastic deformation behavior of bulk metallic glasses (BMGs) is important not only for uncovering the plastic deformation mechanisms but also for achieving better plasticity of BMGs. In the present work, both the cooling-rate and size effects of a Zr-based BMG were investigated by quasi-static compressive experiments. The findings show that the macroscopic plasticity of BMGs can be remarkably enhanced by increasing the casting cooling rate, but moderately improved by decreasing the sample size. The intrinsic atomic arrangement stemming from cooling rate is the primary factor which affects the plastic deformation behavior rather than the extrinsic size effect, and the size effect is also dependent on the intrinsic cooling rate. The findings provide more explanations for the different size effects of BMG communities at different conditions, and are also of significance for achieving better plasticity in BMGs and BMG structures.