Micro-scaled plastic yielding and shear-banding dynamics in metallic glasses.

• A machine compliance, a geometry imperfection of micro-pillar, and a substrate sink-in are studied. • Based on the experimentally measured strengths of 18 metallic glasses at the micrometer scale, a universal criterion for the theoretical elastic strength at micro-scales is proposed. • The study enables the prediction of the strength and estimates the shear band nucleation behavior at the micrometer scale. Shear-banding behavior in metallic glasses plays a key role in the operation of plastic deformation, which is associated with yield strength. In a micro-scale, the shear-banding behavior must be affected by many factors from the test machine and the substrate. Therefore, in this study, comprehensively considering a machine compliance, a geometry imperfection of micro-pillar, and a substrate sink- in the machine-sample-substrate system, we developed a plastic-strength model at a micrometer scale in this study, which is evidenced by the microscale compressive properties of 18 kinds of metallic glasses. The theoretical model provides a guidance for the elastic limits and shear-banding dynamics of metallic glasses at the micro-scale, which can be applicable to characterize the microscale deformation behavior of other amorphous materials. [ABSTRACT FROM AUTHOR]