Grain boundary diffusion and recrystallization in ultrafine grain copper produced by equal channel angular pressing

A model that considers diffusion in nanocrystalline materials undergoing recrystallization was developed. Application of this model enabled us deriving 63Ni radiotracer diffusion coefficients along the grain boundaries in ultrafine grain copper produced by equal channel angular pressing from the experimentally measured radiotracer penetration profiles.

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Grain Boundary Radiotracer Diffusion of Ni in Ultra-Fine Grained Cu and Cu - 1wt.% Pb Alloy Produced by Equal Channel Angular Pressing

Materials Science Forum ◽

10.4028/www.scientific.net/msf.584-586.380 ◽

2008 ◽

Vol 584-586 ◽

pp. 380-386 ◽

Cited By ~ 18

Author(s):

Jens Ribbe ◽

Guido Schmitz ◽

Y. Amouyal ◽

Yuri Estrin ◽

Sergiy V. Divinski

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Equal Channel Angular Pressing ◽

Boundary Diffusion ◽

Ion Beam ◽

Short Circuit ◽

Grain Boundary Diffusion ◽

Coarse Grained ◽

Angular Pressing ◽

Diffusion Paths

The radiotracer technique was applied for measuring grain boundary diffusion of Ni in ultrafine grained (UFG) copper materials with different nominal purities and in a Cu—1wt.%Pb alloy. The UFG specimens were prepared by equal channel angular pressing at room temperature. The stability of the microstructure was studied by focused ion beam imaging. Grain boundary diffusion of the 63Ni radioisotope was investigated in the temperature interval from 293 to 490K under the formal Harrison type C kinetic conditions. Two distinct short-circuit diffusion paths were observed. The first (relatively slow) path in the UFG materials corresponds unambiguously to relaxed high-angle grain boundaries with diffusivities which are quite similar to those in the respective coarse-grained reference materials. The second path is characterized by significantly higher diffusivities. The experimental data are discussed to elucidate the contribution of nonequilibrium grain boundaries in the deformed materials. Alternative contributions of other shortcircuit diffusion paths cannot be ruled out, particularly for the Cu-Pd alloy.

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Acceleration of grain-boundary diffusion at recrystallization in submicrocrystalline metals produced by the method of equal-channel angular pressing

Russian Physics Journal ◽

10.1007/s11182-012-9862-x ◽

2012 ◽

Vol 55 (6) ◽

pp. 649-656

Author(s):

A. V. Nokhrin

Keyword(s):

Grain Boundary ◽

Equal Channel Angular Pressing ◽

Boundary Diffusion ◽

Grain Boundary Diffusion ◽

Angular Pressing ◽

Submicrocrystalline Metals

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Effect of Equal Channel and Dynamic Channel Angular Pressing of Ni and Further Heat Treatment on its Structure and Grain Boundary Diffusion

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.383.96 ◽

2018 ◽

Vol 383 ◽

pp. 96-102 ◽

Cited By ~ 1

Author(s):

Vladimir V. Popov ◽

Gerrit Reglitz ◽

Evgeniy V. Shorohov ◽

E.N. Popova ◽

Alexey V. Stolbovsky ◽

...

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Boundary Diffusion ◽

Grain Boundary Diffusion ◽

Coarse Grained ◽

Internal Stresses ◽

Angular Pressing ◽

Dynamic Channel Angular Pressing ◽

Dynamic Channel ◽

Non Equilibrium

Formation of microstructure in Ni under equal-channel angular pressing (ECAP) and dynamic channel-angular pressing (DCAP), its thermal stability and diffusion properties of grain boundaries are investigated. Grain boundary diffusion in the ultrafine-grained Ni is found to be significantly faster than in the coarse-grained Ni, which indicates a 'non-equilibrium' (deformation-modified) state of grain boundaries in the former. The effect of non-equilibrium state of grain boundaries on the level of internal stresses is analyzed.

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