Critique of mechanisms of formation of deformation, annealing and growth twins: Face-centered cubic metals and alloys

The formation of deformation, annealing and growth twins in face-centered cubic materials is discussed. Slip precedes deformation twinning, and twins form from the interaction between primary and secondary slip dislocations having co-planar, but different, Burgers vectors. The influence of several metallurgical variables on twinning can only be rationalized in terms of the model. Annealing twins form due to growth accidents on differently inclined {1 1 1} facets present on a migrating grain boundary. Growth twins also form by growth accidents on the {1 1 1} planes.