Journal ArticleDOI
The Orowan mechanism in anisotropic crystals
R.O. Scattergood,David Bacon +1 more
Reads0
Chats0
TLDR
The static equilibrium configurations of a dislocation bypassing a periodic row of impenetrable circular obstacles were obtained for various crystals by means of a self-stress method wherein the elastic anisotropy of the crystal and the dislocation self-interaction could be taken into account.Abstract:
The static equilibrium configurations of a dislocation bypassing a periodic row of impenetrable circular obstacles were obtained for various crystals by means of a self-stress method wherein the elastic anisotropy of the crystal and the dislocation self-interaction could be taken into account. A correlation was developed from the results which related the Orowan stress values to the obstacle size and spacing. This correlation demands two parameters to account for the anisotropy, and these appear as a suitably defined anisotropic shear modulus and Poisson's ratio. The self-interactions are taken into account by a single logarithmic parameter which is the harmonic mean of the obstacle size and spacing, and is independent of anisotropy. The shapes of the bowing dislocation loops are strongly influenced by the anisotropy and interactions. The combined effects on shape can bo simply described in the line-tension framework, using the de Wit—Koehler solutions. In particular, the swept areas and overall ...read more
Citations
More filters
Journal ArticleDOI
Superposition of dispersion strengthening and size-mismatch strengthening: Computer simulations
TL;DR: In this article, the critical resolved shear stress (CRSS) is derived and the superposition of two strengthening effects is investigated, and the simulations are based on the local equilibrium of resolved stresses in one glide plane.
Journal ArticleDOI
Interaction between dislocations and precipitates in an AlLi alloy
TL;DR: In this article, a high voltage electron microscope was used to evaluate the obstacle distance and the curvature of bowed out segments of the leading dislocations of pairs, as well as the distance between the pairs of the pairs, under stress.
Journal ArticleDOI
Formation and Anisotropic Mechanical Behavior of Stacking Fault Tetrahedron in Ni and CoCrFeNiMn High-Entropy Alloy
TL;DR: In this article , the authors performed molecular dynamics simulations to verify the applicability of the Silcox-Hirsch mechanism in the CoCrFeNiMn HEA and found that the effects of stacking faults on the elastic properties of Ni and HEA are negligible.
Journal ArticleDOI
Eshelby twist and correlation effects in diffraction from nanocrystals
TL;DR: In this article, the authors used the Debye scattering equation to model the Eshelby dislocation inside Pd and Ir nanowires and to predict the powder diffraction pattern using the powder diffusion pattern.
Book ChapterDOI
The Age Hardening in Copper with Low Concentration of Titanium
TL;DR: In this article, the effect of spinodal decomposition and the formation of ordered regions during the annealing of dilute Cu-Ti alloys on the critical resolved shear stress /CRSS/ increase was studied.
References
More filters
Book
Theory of Dislocations
John Price Hirth,Jens Lothe +1 more
TL;DR: Dislocations in Isotropic Continua: Effects of Crystal Structure on Dislocations and Dislocation-Point-Defect Interactions at Finite temperatures.
Journal ArticleDOI
The effect of dislocation self-interaction on the Orowan stress
TL;DR: In this article, the effect of dislocation self-interaction on the Orowan stress was determined for collinear, impenetrable circular obstacles, and an appropriate integro-differential equation governing static equilibrium was solved by an algorithm based on curvature adjustments.
Journal ArticleDOI
The self-stress of dislocations and the shape of extended nodes
TL;DR: In this article, a definition of the self-stress of a dislocation is proposed which is closely related to the more usual notion of a line tension, enabling a numerical calculation to be made of the shape of extended nodes in dislocation networks, and such a calculation leads to revised values of stacking-fault energies of alloys.
Journal ArticleDOI
Interaction of Dislocations with an Applied Stress in Anisotropic Crystals
G. deWit,J. S. Koehler +1 more
TL;DR: In this article, the equilibrium shape of a dislocation segment between two pinning points in the same glide plane is calculated using an energy per unit length, which is a function only of the angle between the Burgers vector and the tangent to the dislocation.