Changes in the five - parameter grain boundary character distribution in alpha - brass brought about by iterative thermomechanical processing

This paper analyzes the changes in the five-parameter grain boundary character distribution in alpha-brass brought about by iterative thermomechanical processing (ITMP). In both reference and ITMP specimens, there was a tendency for boundaries to terminate on {111} planes. The high incidence of coherent twins and other boundaries terminated on {111} planes led to a high concentration of asymmetric tilt boundaries with <110> misorientations. After ITMP there was a larger population of coherent twins, an increase in the number fraction of Σ9 and Σ27 boundaries, an increase in the fraction of boundaries terminated on {111} planes (even when Σ3 boundaries are excluded), a decrease in the number of triple junctions with three random boundaries, and an increase in the number of triple junctions with three twin related boundaries. The results add strength to the suggestion that ‘special’ boundaries are those which terminate on low index planes.