Abstract
Deformation behavior and local strain evolutions upon loading and unloading of a bulk
metallic glass (BMG) were systematically investigated by in situ digital image correlation
(DIC). Distinct fluctuations and irreversible local strains were observed before the onset of
macroscopic yielding. Statistical analysis shows that these fluctuations might be related to
intrinsic structural heterogeneities, and that the evolution history and characteristics of
local strain fields play an important role in the subsequent initiation of shear bands. Effects
of sample size, pre-strain, and loading conditions were systematically analyzed in terms of
the probability distributions of the resulting local strain fields. It is found that a higher
degree of local shear strain heterogeneity corresponds to a more ductile stressestrain
curve. Implications of these findings are discussed for the design of new materials.
