The structure of a high-angle grain boundary in pure Widmanstätten a-phase, with an axis/angle pair close to [00▪1]/69.43º, was studied by using transmission electron microscopy. The observed dislocation arrangement was modelled by using the O-lattice algorithm for both 2- and 3-dimensional coincidence-site lattice reference structures, and by comparing them with diffraction contrast images. A good fit to the data was obtained for both such structures, in that a good match was obtained between the dislocation line directions and spacings which were observed experimentally and those which were predicted by using the O-lattice algorithm. This showed that the 2 approaches were nearly equivalent for these special cases. However, a network which was obtained by using the 2-dimensional model gave a slightly better fit to the data than did one that was obtained by using the 3-dimensional model.

Analysis of a 69.3º Near-Twist Boundary in Titanium: a Comparison of Two- and Three-Dimensional Models for the Reference Structure. S.Wang, M.Aindow: Materials Science Forum, 1999, 294-296, 309-12