Abstract
The effect of the dependence of grain boundary mobility on misorientation angle and that of structure of the matrix on the growth selectivity during primary and secondary recrystallization are discussed. It was found that the longer is the distance travelled by the growing grain boundaries and the wider the range of the misorientation angles between the new grains and the matrix, the less is the difference between the grain boundary mobilities of the growing grains, necessary for the manifestation of growth selectivity. So during secondary recrystallization the latter is more manifest. In primary recrystallization after moderate deformations, the growth selectivity will be the least obvious when the deformed matrix consists of small differently oriented areas at whose borders new grains nucleate simultaneously. The secondary grain boundaries should be characterized by “effective” mobility, which depends on the number of the adjacent grains and their dimensions, as well as on the growing grain misorientation in relation to these grains. In the small grained material without a texture, the effective boundary mobilities of any grains are equal, and so the growth selectivity in such a material is non-existing.