Results 261 to 270 of about 6,691 (300)

The activation areas for grain boundary sliding

Journal of Materials Science, 1970
The activation areas for grain boundary sliding in Al, Pb, Sn, Zn, and Cu are compared with those for creep in the same materials. It is found that the activation area-stress relation for grain boundary sliding is similar to that for creep. This observation is consistent with a dislocation or ledge mechanism of grain boundary sliding.
N. Balasubramanian, J. C. M. Li
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On the contribution of extrinsic grain boundary dislocations to grain boundary sliding in bicrystals

Acta Materialia, 1997
Abstract The possibility of separating the contributions of extrinsic grain boundary dislocations of different origins to the overall grain boundary shear is shown using the model of grain boundary sliding operating under the conditions of plastic incompatibility.
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Sliding Mechanisms in Aluminum Grain Boundaries

Physical Review Letters, 1997
We present a detailed investigation, based on ensemble density functional theory simulations, of the microscopic mechanisms that accompany the sliding of grain boundaries in aluminum, a typical ductile metal. We find a variety of sliding behaviors, including coupling to migration, that depend not only on the delocalized character of the metallic ...
Molteni, C, Marzari, N, Payne, M C, Heine, V   +3 more
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Mechanism for “Viscous” Grain-boundary Sliding

Nature, 1966
THERE is increasing interest in mechanisms which give plastic deformation at low stresses and moderately high or high temperatures (more than half the melting temperature Tm). Theories of diffusional creep, using either the Nabarro–Herring (NH) mechanism1 based on lattice self-diffusion or Coble's2 variation involving grain-boundary self-diffusion, do ...
R. C. GIFKINS, K. U. SNOWDEN
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Diffusion-controlled true grain-boundary sliding in nanostructured metals and alloys

Materials Science & Engineering A: Structural Materials: Properties, Microstructure and Processing, 2009
For all grain structures studied the activation energy of grain-boundary internal friction is found to exceed the respective one for grain-boundary diffusion but to be lower than the activation energy of bulk diffusion. The diffusion-controlled mechanism
Yu R Kolobov, E V Naydenkin
exaly   +1 more source

Damage, Opening and Sliding of Grain Boundaries

2004
This paper presents an approach to the modeling of damage, opening and sliding of the grain boundaries in zircaloy submitted to stress corrosion cracking. Grain boundaries are seen as a continuous material. The grains are modeled by a model of crystal viscoplasticity.
A. Musienko, G. Cailletaud, O. Diard
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The measurement of grain boundary sliding in polycrystals

Metallurgical transactions, 1974
Measurements on the creep strain attributable to grain boundary sliding, ∈gb, have frequently been performed on the specimen surface. However, thus far there has been no investigation using correct techniques to show that such surface measurements are also representative of the specimen interior.
R. S. Gates, R. N. Stevens
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Grain boundary sliding at low temperatures

Materials Research Proceedings, 2023
Abstract. Grain boundary sliding plays a key role on the high temperature deformation of fine grained materials. This mechanism is related to a high strain rate sensitivity of approximately 0.5 and usually gives rise to high superplastic elongations. The rate controlling equation for the mechanism of grain boundary sliding has shown good agreement with
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Grain Boundary Sliding in Alumina Bicrystals

1966
A technique has been developed for forming bicrystals of alumina with controlled grain boundary orientation by pressure-sintering in vacuo. Bicrystals with tilt misorientations prepared by this technique have been tested in compressive shear and the stress-strain relationship determined. Bicrystal fracture strengths at several temperatures are reported.
M. P. Davis, Hayne Palmour
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Viscous grain-boundary sliding with rotating particles or grains

Acta Materialia, 2009
We evaluate the sliding rate and stress distribution on the boundary when the sliding of grain boundary containing particles is accommodated by grain-boundary diffusion, by taking the particle rotation and the intrinsic boundary viscosity into account. The particle rotation enhances the sliding rate, and can occur in the reverse direction with respect ...
Byung-Nam Kim, Keijiro Hiraga, Koji Morita, Hidehiro Yoshida, Byung-Wook Ahn   +4 more
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