Thermal and plastic behavior of nanoglasses

Abstract

Abstract

Interfacial plasticity governs strain delocalization in metallic nanoglasses

“…Thickening of the interfaces and simultaneous structural relaxation was driven by enhanced atomic mobility at elevated temperatures [30]. The excess free volume and defective short-range order in the interfaces formed at 50 K prior to annealing were initially concentrated within the central regions due to localized flow during consolidation as discussed above and shown in Fig.…”

“…In the Cu-Zr system, the evolution in topological disorder that accompanies compositional changes has been demonstrated to influence the mechanical behavior including both the strength and propensity for localization [21,27]. Increases in strength have also been reported for annealed nanoglass structures and attributed to relaxation of the interfaces influencing the activation of shear transformation zone (STZ) plasticity [3,30]. It is important to note that changes to the interfacial regions will also be accompanied by structural evolution within the amorphous grains [27,28].…”

Thermomechanical processing of metallic glasses: extending the range of the glassy state

“…In compression and tensile tests on micro-pillars, the nanoglasses show substantially better plasticity than melt-spun ribbons; in particular, samples with a 400 nm crosssection exhibit a tensile plasticity of up to 15%, consistent with the more homogeneous flow suggested in simulations 136,137 . This promotion of homogeneous flow 138 is related not only to the overall high free volume, but also to the inhomogeneous structure of the nanoglass, which results in the generation and intersection of multiple shear bands in the soft interfaces. The term nanoglass has been applied also to materials made by methods different from inert-gas condensation and consolidation.…”

Suppression of Shear Banding and Transition to Necking and Homogeneous Flow in Nanoglass Nanopillars

“…Recently, two experimental works on NG were reported. Franke et al 58 investigated the thermal and plastic properties of FeSc NG films. They employed nanoindentation tests to probe the incipient plasticity and the influence of NG interfaces.…”