Rev.Adv.Mater.Sci.(RAMS)
No 1, Vol. 7, 2004, pages 23-31

3-DIMENSIONAL WULFF DIAGRAMS FOR Σ3 GRAIN BOUNDARIES IN Cu

B. Straumal, Ya. Kucherinenko and B. Baretzky

Abstract

The faceting of cylindric tilt grain boundary in Cu bicrystal containing full spectrum of inclinations has been studied at 0.95 of melting temperature Tm. Both grains form the superlattice called coincidence site lattice (CSL) with Σ=3. The (100)CSL facet and non-CSL 82°9R facet are observed. The ratio between GB energy σGB and surface energy σsur was measured by atomic force microscopy using the GB thermal groove method. The influence of misorientation deviation Δψ = |ψ-ψΣ| from coincidence misorientation ψΣ has been studied. The 3-dimensional Wulff-Herring diagrams were constructed using measured σGB / σsur values. They reveal that only (100)CSL and 9R facets correspond to the energy minimum at low Δψ. No rough edges between (100)CSL and 9R facets were observed. It means that Tm is lower than the roughening temperature for these facets in Cu. With increase of Δψ, the energy of (100)CSL facet increases.

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