Abstract :
The investigation reported here extends the conventional approach to the study of the interface
network, by consideration of 3n values up to n = 7 in alpha-brass. All 24
crystallographically-related solutions for each 3n misorientation are included. The study has
shown that multiple annealing twinning does not result in aggregation of higher 3n values
and concomitant reduction in 3s. When a 5◦ deviation from the exact reference misorientation
was used, 20% and 27% of the interface length was 729 and 2187 respectively. This is a
consequence of the increasing number of 3n variants as n increases. Interactions of 3n, often
3 + 3n↔ 3n+1, were observed frequently in the microstructure. The prevalence of
boundaries near to high order 3n attests their importance in the evolution of microstructure.
Analysis of all 24 equivalent solutions for 3n boundaries has shown that approximately half of
these are misoriented on 110 , compared to less than one-third on 111 . The promulgation of
3n boundaries via multiple twinning interaction events promotes and increases the proportion
of 110 tilt boundaries, and to a lesser extent 111 boundaries. These misorientations have
been shown to be associated with low-index boundary planes, and therefore multiple twinning
is instrumental in promoting these ‘special’ planes.
C 2006 Springer Science + Business Media, Inc.
