Void growth in metals: Atomistic calculations

Traiviratana, Sirirat; Bringa, Eduardo M.; Meyers, Marc A.

doi:10.1016/j.actamat.2008.03.047

Cited by 241 publications

(147 citation statements)

References 41 publications

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“…He concluded that the critical stress for nucleation increased for very small voids but did not analyze void growth. Other authors used 3D atomistic simulations to study the nucleation and growth of nm-sized voids [24][25][26][27][28][29][30][31][32] and Potirniche et al [26] reported that smaller voids grew faster at this length scale, a size effect opposed to that found for micrometer-sized voids. However, atomistic simulations of voids growth were limited to very small voids (void radius was below 10 nm) due to the huge computational costs associated with the simulation of larger voids and it is not clear whether the results reported by the analytical and atomistic simulations will hold for larger voids.…”

Section: Introductionmentioning

confidence: 99%

Molecular dynamics modeling and simulation of void growth in two dimensions

Chang¹,

Segurado²,

Fuente³

et al. 2013

Modelling Simul. Mater. Sci. Eng.

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The mechanisms of growth of a circular void by plastic deformation were studied by means of molecular dynamics in two dimensions (2D). While previous molecular dynamics (MD) simulations in three dimensions (3D) have been limited to small voids (up to s«10nm in radius), this strategy allows us to study the behavior of voids of up to 100 nm in radius. MD simulations showed that plastic deformation was triggered by the nucleation of dislocations at the atomic steps of the void surface in the whole range of void sizes studied. The yield stress, defined as stress necessary to nucleate stable dislocations, decreased with temperature, but the void growth rate was not very sensitive to this parameter. Simulations under uniaxial tension, uniaxial deformation and biaxial deformation showed that the void growth rate increased very rapidly with multiaxiality but it did not depend on the initial void radius. These results were compared with previous 3D MD and 2D dislocation dynamics simulations to establish a map of mechanisms and size effects for plastic void growth in crystalline solids.

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Section: Introductionmentioning

confidence: 99%

Molecular dynamics modeling and simulation of void growth in two dimensions

Chang¹,

Segurado²,

Fuente³

et al. 2013

Modelling Simul. Mater. Sci. Eng.

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“…MD has been used extensively to study shock compression mechanisms which require the resolution of atomistic detail [14,15], and is especially useful when heterogeneity [16,17] requires domain sizes too large for density functional theory (QMD-DFT). Sandia's LAMMPS code [18] was used with the Modified Embedded Atom Method (MEAM) [19] and silicon parameters distributed in LAMMPS as Si97 within library.meam [20,21].…”

Section: Methodsmentioning

confidence: 99%

Enhanced densification under shock compression in porous silicon

2014

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Under shock compression, most porous materials exhibit lower densities for a given pressure than that of a full-dense sample of the same material. However, some porous materials exhibit an anomalous, or enhanced, densification under shock compression. We demonstrate a molecular mechanism that drives this behavior. We also present evidence from atomistic simulation that pure silicon belongs to this anomalous class of materials. Atomistic simulations indicate that local shear strain in the neighborhood of collapsing pores nucleates a local solid-solid phase transformation even when bulk pressures are below the thermodynamic phase transformation pressure. This metastable, local, and partial, solid-solid phase transformation, which accounts for the enhanced densification in silicon, is driven by the local stress state near the void, not equilibrium thermodynamics. This mechanism may also explain the phenomenon in other covalently bonded materials.

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“…Finally, the separation of atoms from their neighboring atoms by breaking atomic bonds is the main process attributed to void initiation during plastic deformation. This separation occurs preferentially in brittle particles or at sites where the bond is weaker [68][69]. Therefore, possible features are prone to void nucleation as the heterogeneities found in the microstructure such as the secondphase particles, inclusions, different phase constituents and grain boundaries.…”

Section: Fracture Surface Analysis On Hot Ductilitymentioning

confidence: 99%

Effect of Ti and B microadditions on the hot ductility behavior of a High-Mn austenitic Fe–23Mn–1.5Al–1.3Si–0.5C TWIP steel

Mejı́a

Salas-Reyes

Calvo

et al. 2015

Materials Science and Engineering: A

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a b s t r a c tThis research work studies the effect of combined Ti and B microadditions and the solidification route on the hot ductility behavior of a high-Mn austenitic Twinning Induced Plasticity (TWIP) steel. For this purpose, uniaxial hot tensile tests were carried out at different temperatures between 700 and 1100°C under a constant strain rate of 10. The hot ductility was determined by measuring the reduction of transverse area (%RA) after specimen rupture. Characterization was performed by SEM-EBSD and TEM techniques in order to identify the relationship between microstructural features and cracking phenomena. Results indicate that the early occurrence of dynamic recrystallization (DRX) at the intermediate temperature range (800-900°C) is the favorable mechanism that enhances the ductility, achieving RA values up to 82%. These high RA values are discussed in terms of the boron effect on the improvement of the grain-boundaries cohesion through non-equilibrium segregation, and Ti(C,N) precipitation, which reduces the formation of harmful precipitates such as BN and AlN. Additionally, the Fe 23 (B,C) 6 and B 4 C compounds were identified, which are less detrimental to hot ductility than boron-nitride compounds. Finally, the fracture surfaces of the present TWIP steels in the temperature range of the highest ductility indicate that the failure mode is of the ductile type as evidenced by the presence of many dimples.

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Void growth in metals: Atomistic calculations

Cited by 241 publications

References 41 publications

Molecular dynamics modeling and simulation of void growth in two dimensions

Molecular dynamics modeling and simulation of void growth in two dimensions

Enhanced densification under shock compression in porous silicon

Effect of Ti and B microadditions on the hot ductility behavior of a High-Mn austenitic Fe–23Mn–1.5Al–1.3Si–0.5C TWIP steel

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