grain-boundary diffusion
(rus. зернограничная диффузия)
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diffusion in solid polycrystalline bodies concentrated in narrow (having the thickness of several atomic layers) zones at the boundaries of the grains having different crystallographic orientations.
Description
Due to the high concentration of defects in the grain contact area resulting from their crystallographic misalignment, diffusive transfer along the grain boundaries occurs much faster than in their bulk, where the defect concentration is much smaller (bulk diffusion), but slower than in the boundary between the solid and the atmosphere (surface diffusion). Grain-boundary diffusion is one of the main mechanisms of low-temperature sintering used in ceramics manufacturing and powder metallurgy; increase in its contribution is usually thought to be the reason of a lower sintering temperature when finely-dispersed raw materials are used. Grain-boundary diffusion is also one of the deformation mechanisms in solids."
Author
- Shlyakhtin Oleg A.
Sources
- "Atkinson A. Grain-boundary Diffusion: An Historical Perspective // J. Chem. Soc. Dalton Trans. 1990. V. 86, №8. P. 1307–1310.
- Ovid'ko I. A., Rejjzis A. B. Grain-Boundary Dislocation Climb and Diffusion in Nanocrystalline Solids // Physics of the Solid State, Vol. 43, No. 1, 2001, pp. 35–38.
- Translated from Fizika Tverdogo Tela, Vol. 43, No. 1, 2001, pp. 35–38, http://mp.ipme.ru/ipme/labs/ltdm/FTT_diffusion.pdf (reference date: 12.12.2011)."