Twin-intersection-related nanotwinning in a heavily deformed gamma-TiAl-based alloy.

Nanotwins related to the type-I twin intersection in gamma-TiAl have been investigated by high-resolution electron microscopy. A triangular striated region can be formed around the twin intersection. Some nanotwins were observed to nucleate through interfacial dislocation reactions on the incoherent twin boundary of the triangular striated region. The nanotwins, which propagate by a twinning dislocation homogeneous glide mechanism, are mostly limited to the triangular striated region. [ABSTRACT FROM AUTHOR]