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Is it safe to assume that the change in a dislocations' burger's vector size is negligible during loading?

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As a result of loading, there is grain distortion, which results in lattice distortion. when lattice distortion happens, then lattice parameter changes. The change in lattice parameter, (a), results in a dislocation's burger's vector size change, since it has the lattice parameter size in its formula. Consequently, one can conclude that the size of burger's vector of a dislocation changes as a result of loading! . Still, is it practically safe to assume that the the change in its size is negligible compared to its initial size before loading?

Is there a way to measure the magnitude of a dislocation burger's vector via high precision optical microscopes?

I need to calculate the size or magnitude of the burger's vector of a dislocation in crystalline materials, metals. Obviously and typically, it can be measured via XRD or the electron microscopy methods, TEM and SEM. The question is:

could it also be measured via high precision optical microscopes, as precise as 1nm ?

mohsenzaeem's picture

Competing mechanisms between dislocation and phase transformation in plastic deformation of single crystalline yttria-stabilized tetragonal zirconia nanopillars

Molecular dynamics (MD) is employed to investigate the plastic deformation mechanisms of single crystalline yttria-stabilized tetragonal zirconia (YSTZ) nanopillars under uniaxial compression. Simulation results show that the nanoscale plastic deformation of YSTZ is strongly dependent on the crystallographic orientation of zirconia nanopillars. For the first time, the experimental explored tetragonal to monoclinic phase transformation is reproduced by MD simulations in some particular loading directions.

Harley T. Johnson's picture

A critical thickness condition for graphene and other 2D materials

B. C. McGuigan, P. Pochet, and H. T. Johnson, Critical thickness for interface misfit dislocation formation in two-dimensional materials, Phys. Rev. B 93, 214103, 2016.


In Situ Atomic-Scale Observation of Twinning Dominated Deformation in Nanoscale Body-Centred Cubic Tungsten

In situ atomic-scale observation of twinning-dominated deformation in nanoscale body-centred cubic ​tungsten

By Jiangwei Wang, Zhi Zeng, Christopher R. Weinberger, Ze Zhang, Ting Zhu & Scott X. Mao

Nature Materials (2015) doi:10.1038/nmat4228

Ting Zhu's picture

Surface dislocation nucleation


  Surface dislocation nucleation

Ting Zhu, Ju Li, Amit Samanta, Austin Leach and Ken Gall, “Temperature and strain-rate dependence of surface dislocation nucleation”, Physical Review Letters, 100, 025502 (2008).

Cai Wei's picture

Dislocations 2008 International Conference

We are pleased to announce Dislocations 2008, an international conference on the fundamentals of plastic deformation and other physical phenomena where the dislocations play pivotal roles.  The conference will take place on October 13-17, 2008 at the Gold Coast Hotel, Hong Kong, China.  More information about the Dislocations 2008 conference can be found at the following web site:

Kejie Zhao's picture

Question: Is the local energy dictating dislocation emission constant for single crystal?

Hi everyone, in my size dependence study, I find the local energy dictating dislocation emission is almost constant for varied sized samples, in given directions of single crystal. I don't know this is an interesing finding, or just a common sense. Will you give me some suggestion, Thank you!


Honghui Yu's picture

Integral Formulations for 2D Elasticity: 1. Anisotropic Materials

Might also be useful for simulating dislocation motion in a finite body.

Several sets of boundary integral equations for two dimensional elasticity are derived from Cauchy integral theorem.These equations reveal the relations between displacements and resultant forces, between displacements and tractions, and between the tangential derivatives of displacements and tractions on solid boundary.Special attention is given to the formulation that is based on tractions and the tangential derivatives of displacements on boundary, because its integral kernels have the weakest singularities.The formulation is further extended to include singular points, such as dislocations and line forces, in a finite body, so that the singular stress field can be directly obtained from solving the integral equations on the external boundary without involving the linear superposition technique often used in the literature. Body forces and thermal effect are subsequently included. The general framework of setting up a boundary value problem is discussed and continuity conditions at a non-singular corner are derived.  The general procedure in obtaining the elastic field around a circular hole is described, and the stress fields with first and second order singularities are obtained. Some other analytical solutions are also derived by using the formulation. 

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