Activation volume and energy of bulk metallic glasses determined by nanoindentation

Testing Effects on Shear Transformation Zone Size of Metallic Glassy Films Under Nanoindentation

“…In recent years, following the cooperative shear model (CSM) by Johnson and Samwer [11], Pan et al developed an experimental method to estimate STZ volume relying on strain rate sensitivity (SRS) through rate-jump nanoindentation [12,13,14]. In Pan’s work, STZ size displayed a strong correlation with Poisson’s ratio and structure state [12,15], and could be closely tied to the ductility of bulk metallic glasses.…”

On the origin of softening in the plastic deformation of metallic glasses

“…What's more, as mentioned above, the creep stage of nanoindentation characterizes the "delayed plasticity" of materials being plastically deformed underneath the indenter, and thus depends intimately on the softened deforming state of the MGs in the loading stage, providing a critical resort to examining "quasi in-situ" the softening effect in the plastic deformation of MGs, unlike the post-mortem tests having been done previously (Pan et al, 2018). For the complicated stress state under the indenter and utilizing the absence of dilatation in crystalline structures, a systematic study on the MGs before and after crystallization is necessary to thoroughly understand the plastic deformation of MGs in nanoindentation (Burgess and Ferry, 2009;Castellero et al, 2008;Kramer et al, 2018;Wang et al, 2018b;Yang et al, 2016b).…”

Phase transition and nanomechanical properties of refractory high-entropy alloy thin films: effects of co-sputtering Mo and W on a TiZrHfNbTa system

“…Different from dislocation mechanisms in the nanocrystalline TiZrHfNbTa, shear transformation zones (STZ) related mechanisms are considered the deformation mechanism in the amorphous TiZrHfNbTaMo and TiZrHfNbTaW. 50 Diffusion processes may govern the plastic deformation of the amorphous TiZrHfNbTaMo and TiZrHfNbTaW, 51 leading to more consistent SRS in a wide range of strain rates.…”