The effect of size on the elastic strain limit in Ni60Nb40 glassy films

On small-sized Ni60Nb40 magnetron-sputtered glassy films confined by frame, we experimentally revealed a significant size effect on the elastic strain limits by in situ transmission electron microscopy observations. Ni60Nb40 glassy films with thicknesses of 50, 100 and 200 nm exhibit elastic strain limits of 6.5-6.6%, 4.7-4.9% and 3.5-3.6%, respectively. No effects of changing length or width, or the ratio of width or length to thickness on the elastic strain limit are detected in the studied ranges. The size effect could be attributed to different open volumes in the magnetron-sputtered Ni60Nb40 films with various thicknesses, indicating that controlling the open volumes might be a useful way to tailor the properties of metallic glassy materials. The current findings provide a new way to understand the tensile deformation behavior of metallic glasses and supply an effective approach to enhance the elastic strain limit of metallic glasses. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.