A Peierls-Nabarro model for kink-pair generation in screw dislocations at low temperatures
01 Jan 1998-MRS Proceedings (Materials Research Society. The Journal's web site is located at http://www.mrs.org/publications/epubs/proceedings/spring2004/index.html)-Vol. 538, Iss: 1, pp 113-118
TL;DR: In this paper, the authors investigated kink-pair generation in three-fold screw dislocations in the bcc lattice under the framework of the generalised Peierls-Nabarro model.
Abstract: Kink-pair generation in three-fold screw dislocations in the bcc lattice is investigated within the framework of the generalised Peierls-Nabarro model. Using a piece-wise plane strain approximation, the apparent activation energy is predicted to vary with stress in a parabolic manner which is in good agreement with experimental findings.
Citations
More filters
8 citations
References
More filters
TL;DR: In this paper, the anisotropy of plasticity in b.c. metals is decomposed into two parts: a sensitivity of the Peierls stress to non-glide elements of the applied stress, and small edge fractional dislocation components in the screw dislocation core.
442 citations
TL;DR: In this article, the elastic energy of the activated bulges in dislocations is fully taken into account in a quasi-anisotropic calculation by making it trapezoidal.
Abstract: Analysis of the temperature dependence of the flow stress of the b.c.c. metals α-Fe, Nb, Mo and Ta reveals their Peierls potentials. They are dam-like with a flat maximum or even have an intermediate minimum, but they are never sinusoidal. The elastic energy of the activated bulges in the dislocations is fully taken into account in a quasi-anisotropic calculation by making it trapezoidal. In the thermally activated configuration the amplitude of the bulge (the height of a kink pair) is the lattice periodicity a, double activation to 2a is excluded.
73 citations
TL;DR: In this paper, the core structures and lattice friction stresses of single kinks on a screw dislocation in the b.c. lattice have been calculated by means of computer simulation.
69 citations
TL;DR: In this paper, a generalized Peierls-Nabarro model is developed to take into account the nonplanar mode of dissociation for screw dislocations, which can be obtained by a self-consistent numerical scheme.
Abstract: The original Peierls-Nabarro model considers planar dissociation only and is therefore not valid for screw dislocations which have more than one slip plane In this work, a generalized Peierls-Nabarro model is developed to take into account the non-planar mode of dissociation for screw dislocations Solution to the governing integral equation can be obtained by a self-consistent numerical scheme The equilibrium configuration, strain and stress fields, and the energy of the dislocation core can be calculated from this model
57 citations