Atomistic Determination of Cross-Slip Pathway and Energetics

Rasmussen, T.; Jacobsen, Karsten Wedel; Leffers, T.; Pedersen, O.B.; Srinivasan, Shriram; Jónsson, Hannes

doi:10.1103/physrevlett.79.3676

Cited by 102 publications

(49 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Perhaps, more importantly, we view our analysis as a first step towards the more judicious management of boundary conditions associated with complex three-dimensional geometries involving dislocations. In particular, recent work on both dislocation junctions [22][23][24] and cross slip [25,26] are a significant first step towards informing higher-level dislocation dynamics simulations of plasticity on the basis of an atomiclevel understanding of the 'unit processes' involving dislocations. One of the key challenges faced in effecting calculations that are quantitatively meaningful is combatting the spurious effects induced by the presence of unwanted nearby boundaries.…”

Section: Discussionmentioning

confidence: 99%

Lattice resistance and Peierls stress in finite size atomistic dislocation simulations

Olmsted

Hardikar

Phillips

2001

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

Atomistic computations of the Peierls stress in fcc metals are relatively scarce. By way of contrast, there are many more atomistic computations for bcc metals, as well as mixed discrete-continuum computations of the Peierls-Nabarro type for fcc metals. One of the reasons for this is the low Peierls stresses in fcc metals. Because atomistic computations of the Peierls stress take place in finite simulation cells, image forces caused by boundaries must either be relaxed or corrected for if system size-independent results are to be obtained. One of the approaches that has been developed for treating such boundary forces is by computing them directly and subsequently subtracting their effects, as developed in (Shenoy V B and Phillips R 1997 Phil. Mag. A 76 367). That work was primarily analytic, and limited to screw dislocations and special symmetric geometries. We extend that work to edge and mixed dislocations, and to arbitrary two-dimensional geometries, through a numerical finite element computation. We also describe a method for estimating the boundary forces directly on the basis of atomistic calculations. We apply these methods to the numerical measurement of the Peierls stress and lattice resistance curves for a model aluminium (fcc) system using an embedded-atom potential.

show abstract

Section: Discussionmentioning

confidence: 99%

Lattice resistance and Peierls stress in finite size atomistic dislocation simulations

Olmsted

Hardikar

Phillips

2001

Modelling Simul. Mater. Sci. Eng.

View full text Add to dashboard Cite

show abstract

“…The construction energy U for Cu obtained in MD simulation was shown to be in the same range as that obtained from dislocation theory for recombining two partials from their equilibrium distance [26]. Here, we use the recombination energies from dislocation theory as the values of U for Al, Cu and Ni in numerics.…”

Section: Evaluating Strengthening At Tbmentioning

confidence: 99%

Strengthening at nanoscaled coherent twin boundary in f.c.c. metals

Dao

Zhu

2014

Philosophical Magazine

View full text Add to dashboard Cite

This paper analyses slip transfer at the boundary of nanoscaled growth twins in face-centred cubic (f.c.c.) metals for strengthening mechanism. The required stress for slip transfer, i.e. inter-twin flow stress, is obtained in a simple expression in terms of stacking fault energy and/or twin boundary (TB) energy, constriction energy and activation volume. For nanotwinned Al, Cu and Ni, inter-twin flow stress versus twin thickness remarkably shows Hall-Petch relationship. The Hall-Petch slope is rationalized for various reactions of screw and non-screw dislocations at the TB. Additionally, strengthening at the boundary of nanoscaled deformation twins in f.c.c. metals is analysed by evaluating required twinning stress. At small nanograin size, the prediction of deformation twin growth stress shows inverse grain-size effect on twinning, in agreement with recent experimental finding.

show abstract

“…The two determining factors in the dislocation density of deformed metals are the dislocation multiplication and annihilation rates. At ambient temperature, where climb processes are limited, dislocation annihilation occurs only via cross slip of screw dislocation [8]. In this Letter we investigate the activated annihilation of a dipole with height h 1.3 nm.…”

Section: (Received 16 June 2000)mentioning

confidence: 99%