Three‐dimensional imaging of shear bands in bulk metallic glass composites

Summary The mechanism of the increase in ductility in bulk metallic glass matrix composites over monolithic bulk metallic glasses is to date little understood, primarily because the interplay between dislocations in the crystalline phase and shear bandsin the glass could neither be imaged nor modelled in a validated way. To overcome this roadblock, we show that shear bandscan be imaged in three dimensions by atom probetomography from density variations in the reconstructed atomic density, which density-functional theory suggests being a local-work function effect. Imaging of near-interface shear bandsin Ti48Zr20V12Cu5Be15 bulk metallic glass matrix composite permits measurement of their composition, thickness, branching and interactions with the dendrite interface. These results confirm that shear bandshere nucleate from stress concentrations in the glass due to intense, localized plastic deformation in the dendrites rather than intrinsic structural inhomogeneities.