Effects of Fe atoms on hardening of a nickel matrix: Nanoindentation experiments and atom-scale numerical modeling

Mechanisms of strength and hardening in austenitic stainless 310S steel: Nanoindentation experiments and multiscale modeling

“…Several new elements can be summarized: 1) The analysis of the nanoscale anisotropic elastic-plastic behavior of SS nanoindentation, as well as pile-up patterns and atomic strains distribution using molecular dynamics (MD) simulations; 2) The elucidation of atomistic mechanisms of dislocation nucleation and defects evolution by suitable nano-indentation tests in SS by comparison to equiatomic Ni-Fe solid solutions under identical conditions 24 ; 3) The verification of the connection between geometrically necessary dislocations (GND) and size effects based on dislocation dynamics and associated continuum modeling. From our results, we can argue that low-carbon austenitic stainless steel 310S indi- cates anisotropic properties and the insights into lattice defect dynamics may provide a basis for understanding the physical mechanisms associated with its deformation making it a good candidate for applications in nuclear power plants and extreme operating environments.…”

“…For the equiatomic Ni-Fe concentrated solid solution Alloy, we utilized a potential interatomic reported by Choi et al 29 which are based on the second Nearest Neighbor Modified Embedded Atom Method (2NN-MEAM). The numerical cell defined as: (33.08x, 35.95y, 30.97z) and with 1 582 400 Ni and 1 582 400 Fe atoms, as reported in our previous work 24 .…”

“…In plementary material. In order to report the effects on chemical complexity of the material on the mechanical properties, we compare results to those reported for an equiatomic single-phase concentrated solid solution alloy (SP-CSA) defined as NiFe 24 for experimental and computational modeling. We noticed that the hardness of the binary alloy smoothly decreases as a function of the depth for both methods.…”

“…Concomitantly, Molecular Dynamics (MD) simulations have proven to be a powerful tool to emulate experimental nanoindentation tests. MD may provide atomistic insights to the mechanical response of indented samples and defect mechanisms [19][20][21][22][23][24][25] , information that cannot be clearly seen through Load -Displacement (L-D) curves. The major advantage of MD simulations is the ability to investigate the thermomechanical stability of dislocation nucleation and defects' evolution [19][20][21][22][23] .…”

“…We demonstrate a detailed experimental and computational study to understand the nanoscale plastic deformation mechanisms and anisotropy effects in polycrystalline SS 5,26 and develop a multiscale description, using constitutive modeling. For the understanding of dislocation nucleation and evolution mechanism in SS during nanoindentation tests, we compare our MD results with the simpler, already studied, case of equiatomic FCC Ni-Fe solid solutions 24 under similar thermomechanical conditions. Then, by visualizing and quantifying dislocation ensembles, we develop a continuum plasticity model for the defect evolution in SS.…”