An instrumented indentation study on mechanical behavior of bulk metallic glasses across multi-scale from macro to nano level

Abstract

Due to its several advantages based on simple and easy testing procedure, now instrumented indentation test is widely performed to evaluate mechanical phenomena of amorphous alloys which show very different deformation behaviour from those of crystalline materials. In this study, to gain new insights for the mechanical behaviour in bulk metallic glasses, a series of instrumented indentation experiments were performed on various bulk metallic glasses with geometrically self-similar sharp indenters (having different indenter angle) as well as spherical indenters (having different tip radius). Each indenter tip is expected to induce different stress field under the indenter, and thus comparison of the results might provide somewhat new and valuable information about mechanical behaviours and properties of bulk metallic glasses. Especially for the spherical indentations exhibiting the continuous evolution of plasticity, different indentation load levels were applied using both macro- and nano-indentation equipments. Results are discussed in terms of prevailing ideas for shear-band-ruled deformation behaviours in the glasses.