Figure 4. Fast Fourier transform model set-up.

Schematic representation of the tricrystal unit cell. The twin is embedded in a central grain (grain 1) and the twin front is arrested at the grain boundary with the neighbouring grain (grain 2). A buffer layer of random orientations surrounds the tricrystal. This configuration represents a polycrystal in which only three grains are magnified for numerical simulation purposes. The region Ω in the neighbouring grain is the potential region where twin transmission may occur and where the stresses available for twin transmission are calculated.