The effect of stress on the cross-slip energy in face-centered cubic metals: A study using dislocation dynamics simulations and line tension models

Abstract

Dislocation dynamics simulations were used to calculate the energy barrier of cross-slip via Friedel-Escaig mechanism in face centered-cubic copper. The energy barrier in the unstressed case was found to be 1.9 eV, as reported by B. Ramírez et al. [1] . The energy barrier was reduced by applying an external stress. The most effective way of reducing it, was by applying a compressive stress on the glide plane. Furthermore, it was confirmed using dislocation dynamics simulations, that both the Schmid and Escaig stress have a comparable effect in reducing the energy barrier, in qualitative agreement with the atomistic simulations performed by K. Kang et al. [2] in face-centered cubic nickel. Most of the energy barrier values for stressed cross-slip fell within the experimental error of 1.15±0.37 eV measured by J. Bonneville et al. [3] . Moreover, the activation enthalpy obtained from K. Kang's et al. [2] line tension model of cross-slip and the general expression for the activation enthalpy proposed by A. Malka-Markovitz et al. [4] were in good quantitative agreement with the simulation results. Hence, both could be used to calculate the activation enthalpy of screw segments in dislocation dynamics simulations.

Effect of Microstructure on the Dimensional Stability of Extruded Pure Aluminum

“…The complex network of LAGBs was developed during thermal cycling, as can be seen from the histograms of the misorientation angle. It could be validated that the complex stress state was induced by thermal cycling, resulting in the formation of a dislocation network and substructures [50,51]. The misorientation of these substructures was gradually increased as the number of thermal cycles increasing until equiaxed grains were formed.…”

Investigating the cross-slip rate in face-centered cubic metals using an atomistic-based cross-slip model in dislocation dynamics simulations

“…In fact, Kang et al (2014) showed that both stress components have a comparable effect on the activation enthalpy. This assertion has been thoroughly verified using different formulations of the Line Tension (LT) model (Kang et al, 2014;Liu et al, 2019;Longsworth and Fivel, 2021), linear-elasticity models (Longsworth and Fivel, 2021;Kuykendall et al, 2020) and atomistic simulations (Kang et al, 2014;Esteban-Manzanares et al, 2020;Kuykendall et al, 2020;Liu et al, 2019). Therefore, the influence of all the stress components should be considered in the cross-slip rate.…”

“…25. The only free parameter in the theory of Malka-Markovitz and Mordehai ( 2019) is the unstressed energy barrier ∆E 0 , which can be obtained either from line tension models (Kang et al, 2014;Malka-Markovitz and Mordehai, 2019), atomistic simulations (Oren et al, 2017;Liu et al, 2019;Esteban-Manzanares et al, 2020;Kuykendall et al, 2020) or DD simulations (Ramírez et al, 2012;Longsworth and Fivel, 2021). In the present paper, the energy barrier of FCC copper ∆E 0 = 1.9 eV was obtained from DD simulations (Longsworth and Fivel, 2021) to make the work independent of other numerical results.…”

“…They reported a reasonable agreement between their atomistic simulations and LT model for α values in the range from 0.1 to 0.6. In a previous work (Longsworth and Fivel, 2021), the line-energy parameter was calibrated using the LT model of Kang et al (2014). In order to obtain an unstressed energy barrier of 1.9 eV in FCC copper, the line-energy parameter was adjusted to 0.22.…”

Fatigue life prediction method of face‐centered cubic single‐crystal metals under multiaxial nonproportional loading based on structural mechanical model

“…Additionally, alloying can reduce the material split level energy and thereby realize the simultaneous improvement of material strength and plasticity. [10][11][12] Various studies have [13][14][15][16][17][18] used molecular dynamics theory to simulate the evolution of FCC unit cell dislocations. He et al 19 proposed a single-bit error-based model to quantitatively predict the stress-strain behavior of micron-scale FCC and bodycentered cubic metal cells.…”