screw dislocation

screw dislocation

[′skrü ‚dis·lō‚kā·shən]
(crystallography)
A dislocation in which atomic planes form a spiral ramp winding around the line of the dislocation.
References in periodicals archive ?
1: A stationary screw dislocation in cartesian (x, y, z) and cylindrical polar (r, [theta], z) coordinates.
The underpinning results of Li and Liu [14] on the physical property tensors enabled Wang and Pan [15] to give detailed closed-form representations of the field components of a screw dislocation moving uniformly in one-dimensional hexagonal piezoelectric quasicrystals.
In order to gain a clear idea of the most important factor which influences the dislocation preferential formation site of mixed dislocation at the plane perpendicular to the QD growth direction in InAs quantum dots, we decompose the 60[degrees] mixed dislocation into two edge dislocation components with Burgers vector [110] and [00 - 1], respectively, and a screw dislocation component with Burgers vector [-110].
Suppose that a piezoelectric material is transversely isotropic and containing a charged screw dislocation around a finite crack of length 2a as shown in Fig.
A prime example is the presence of a screw dislocation in a crystal (Fig.
In older walls, well proximal of growing edges, large areas of the wall surface may be covered by crystallites that have undergone multiple divisions by screw dislocation, or by step-like splitting.
investigated Peierls stress of a screw dislocation below a free surface via a self-consistent semidiscrete variational P-N model using image dislocation method [10].
There are two types of dislocations: an edge dislocation for which [b.sup.[mu]][[xi].sup.[mu]] = 0 and a screw dislocation which can be right-handed for which [b.sup.[mu]][[xi].sup.[mu]] = b, or left-handed for which [b.sup.[mu]][[xi].sup.[mu]] = -b, where b is the magnitude of the Burgers vector.
If we consider a stationary screw dislocation in the spacetime continuum, with cylindrical polar coordinates (r, [theta], z), with the dislocation line along the z-axis (see Fig.
Wei [13] investigated the impingement of a screw dislocation on intrinsic stacking fault (SF) and extrinsic stacking faults (ESF) in different FCC metals by using the molecular dynamics simulations, which were significant to further understand the details of plastic deformation and to seek the underlying techniques for strengthening metals; Dey et al.
A screw dislocation can cut another screw dislocation and generate a close-packed line of vacancies and interstitials similar to it glides with the point defect produced depending on the relative Burgers vectors of the intersecting dislocations Because strain energy related to vacancy is smaller than with related to interstitial atom the vacancies are formed in larger number than interstitial atoms.