The role of the grain boundary plane in cubic polycrystals

This paper presents an appraisal of investigations which feature statistics of grain boundary plane distributions in polycrystals. The approach taken is to set the review against a background which includes the significance of the grain boundary plane parameter and several methodologies for its investigation in both bicrystals and polycrystals, including high resolution electron microscopy and computer simulation. The digest of data in polycrystals is analysed in the light of tilt and twist characteristics, boundary plane reorientation, the occurrence of low-index boundary planes and correlation with boundary properties. It emerges that the key factors which control the crystallography of boundary planes are the combined effects of material type, twinning (where applicable), microtexture, proximity to a coincidence site lattice and boundary plane inclination with respect to the macroscopic specimen geometry. Grain boundary plane engineering, wherein CSL categorisation is secondary to boundary plane crystallography. is recommended as a more advanced approach and its feasibility is demonstrated. (C) 1998 Acta Metallurgica Inc.