High-resolution transmission electron microscope studies showed that the morphology of twin layers near to a twin tip could be characterized as being of semi-lenticular shape. The twinning dislocation array was on only one side of the twin layer which formed a curved incoherent twin boundary, and the other side of the twin layer was a flat coherent twin interface. The form of the present twin tip was the result of a perfect glide dislocation interacting with the twinning boundary.

HREM Observation of the Tip of a Deformation-Induced γ Twin in a TiAl Alloy. J.X.Zhang, H.Q.Ye: Journal of Materials Science Letters, 2001, 20[1], 9-10