Back-stress distribution along a thin twin layer in TiAl

Mechanical twinning has been found to be an important deformation mechanism in TiAl. However, the details of mechanical twinning mechanisms, such as how mechanical twins nucleate and propagate in TiAl, are not clear, although some fundamental investigations on twin propagation and twin intersections have been pursued. In order to clarify the mechanical twin nucleation and propagation mechanisms in TiAl and the necessary stress conditions for twin propagation in TiAl, the back-stress distribution along a thin twin layer is investigated. The result shows that the back stress drops very quickly near the twin tip and becomes smaller as the distance from the twin tip increases.