Depinning transition for a screw dislocation in a model solid solution

Abstract

On the basis of the classical dislocation theory, the Solid Solution Hardening (SSH) is commonly ascribed to the pinning of the edge dislocations. At the atomic level, the theoretical study of the dislocation cores contrasts with such a prediction. Using the static molecular simulations with some interatomic effective potentials, we demonstrate numerically that the critical resolved shear stress associated to a screw dislocation in a random Ni(Al) single crystal has same order as the edge one. Such a result is imposed by the details of the dislocation stacking fault and the core dissociation into Shockley partials. The SSH statistical theory is employed to tentatively predict analytically the data acquired through our atomistic simulations at different Al concentration.

References in corpus (5)

• Creep and depinning in disordered media
• Atomistic simulations of dislocation mobility in Al, Ni and Al/Mg alloys
• Pinning and Sliding of Driven Elastic Systems: from Domain Walls to Charge Density Waves
• Numerical Calculation of the Functional renormalization group fixed-point functions at the depinning transition
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Cited by in corpus (4)

• Strengthening magnesium by design: integrating alloying and dynamic processing
• Depinning of a discrete elastic string from a two dimensional random array of weak pinning points
• Substitutional Al solute interaction with edge and screw dislocation in Ni: a comparison between atomistic computation and continuum elastic theory
• Solute softening and vacancy generation by diffusion-less climb in magnesium alloys