The first observations of a new structural feature of the 2 phase in quenched Ti-46.54Al alloy were reported. This feature had the appearance of very straight long bands, and had the same structure, lattice parameters and composition as the 2 matrix; with a (31¯42)[3¯635] twin relationship with respect to the matrix. Short twin segments along these long twins, with a (¯2201)[1¯104] twin relationship with respect to the 2 matrix, were also observed. Thin stacking faults and/or  layers were occasionally present within them. These structural features were thought to form in the high temperature  phase during rapid quenching; probably via a double twinning mechanism.

P.Wang, D.Veeraraghavan, V.K.Vasudevan: Scripta Materialia, 1996, 34[10], 1601-7