Size effects and ductility of Al-based metallic glass

This paper reports the results of compression tests conducted in situ in a transmission electron microscope of taper-free nanosized pillars of Al86Ni9Y5 metallic glass with diameters ranging between 110 and 900 nm. A critical size was found, below which the deformation mode changes from intermittent shear banding to homogeneous flow. The threshold size for the transition from brittle to ductile behavior is 300 nm in Al86Ni9Y5. Such a high plasticity has not been found previously in metallic glasses of these dimensions. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.