An attempt was made to 'fine tune' or reorient grain-boundary planes within the interior of a specimen after annealing in air. Particular attention was paid to S = 3 boundaries. The initial heat-treatment consisted of annealing in air (900C, 1h). This resulted in a population of S = 3 boundaries which was largely displaced from low-energy configurations and was a so-called snapshot of interrupted grain growth. Control specimens were further annealed in air (540C, 97h) with the aim of reorienting the grain-boundary plane population. This was possible because the entire S = 3 population was close to the lowest-energy configuration. The data were explained in terms of nucleation and impingement twins, as well as in terms of atomic-level faceting of vicinal boundaries into special facets plus steps. This strategy indicated a useful link between macroscopic boundary plane experiments and the results of high-resolution electron microscopy.

Grain-Boundary Plane Reorientation in Copper. V.Randle, P.Davies, B.Hulm: Philosophical Magazine A, 1999, 79[2], 305-16