Multiscale analysis of nanoindentation-induced defect structures in gum metal

Abstract

Using ex-situ transmission electron microscopy and the recently developed nanoprobe diffraction (NPD) technique, we characterize a nanoindented solution treated gum metal.Lattice rotations are resolved at a 1.2 nanometer length-scale and shown to be continuous within the nanoindentation pit; further, it is shown that these can be accommodated by a reasonable number of geometrically necessary dislocations at a density of ~10^15/m 2 . We additionally provide direct evidence that dislocations within the nanoindent, rather than secondary phase nanoparticles, can serve as potent barriers to dislocation motion. We also demonstrate that plasticity in these alloys under nanoindentation can be accommodated solely by dislocation nucleation and propagation, with no competing deformation mechanisms present. Conventional transmission electron microscopy and "gb" analysis reveal the presence of dislocations on <-111>{110} slip systems and highly localized plastic deformation in the form of shear bands on <111>{-1-12} slip systems, similar to previously observed "giant faults". Keyword

Molecular Dynamics Simulation of the Nanoindentation of Coal Vitrinite

“…), DSNI is a type of quantitative method for characterizing the nanoscale mechanical properties of substrate materials (Nili et al, 2013). So far, DSNI has already been applied for studying the mechanical properties of lots of materials, including composites, polymers, metals, and crystals (Sankaran et al, 2018;Yuemin Wang et al, 2020;Han et al, 2021;Isik et al, 2022). In recent years, this technology has received increased attention in coal research (Vranjes et al, 2018;Zhang et al, 2018;Sun et al, 2020a;Sun et al, 2020b;Kossovich et al, 2020).…”