Extraction of bulk metallic-glass yield strengths using tapered micropillars in micro-compression experiments

In this paper, a formula is derived based on the Mohr-Coulomb law to extract the bulk metallic-glass (BMG) yield strengths in the micro-compression experiments, accounting for the effects of a variety of geometrical parameters arising from the tapered micropillar geometries. The experimental results on three classes of BMGs, comprising the Zr-, Mg- and Fe-based BMGs, show that the yield strengths of the BMG micropillars exhibit a very weak size effect as compared with the literature data obtained from the micro-crystals. The validity of the derived formula is then checked through the comparison with the measurements from the nanoindentation and macro-compression experiments.