On the role of orientation correlations in the grain boundary character distribution of textured polycrystals

In recent years, relationships between grain boundary misorientation distributions and texture have been studied bath experimentally and by means of computer simulation. While there have been attempts to derive misorientation distributions from texture data only, our studies have shown that, in general, the relationship between the two distributions is not straightforward. Complications arise due to the orientation correlations which may exist between various crystallites of the polycrystalline aggregate. These two factors, texture and orientation correlations, determine the grain boundary character distribution in a sample. Contributions of these factors to the misorientation distribution as a whole and to the fractions of specific grain boundary types are dependent on the material. In some materials, for example BCC allays, grain boundary distribution is primarily determined by texture. However, the orientation correlations play a dominant role in FCC alloys. The same may be true for other materials with a high propensity to formation of special (twin) boundaries. The results obtained on nanocrystalline monoclinic zirconia film give evidences in favor of this conclusion.