Study on the stress-induced γ → α2 transformation in a hot-deformed Ti-45Al-10Nb alloy by high-resolution transmission electron microscopy

Cyclic deformation and lattice strain distribution of high Nb containing TiAl alloy

“…Based on this point, possible lamellar refining mechanisms were proposed for the investigated TiAl alloy low cycle fatigued at 750 and 900 °C. The microstructure degradation of TiAl alloy cyclic deformed at room temperature may mainly resulted from stress-induced γ → α2 phase transformation process, which also reported by Wang et al [32].…”

High-resolution image simulation of overlap structures in TiAl alloy

“…Though most of the interfaces between the ␥ and ␣ 2 laths are edge-on if the incident electron beam projects into the specimens along the 1 1 0 ␥ || 1 12 0 ␣ 2 direction, as relatively unusual cases, the overlap structures consisting of two twin-related ␥ laths or of the ␥ and ␣ 2 phases have also been examined many times in full-lamellar TiAl alloys [9][10][11][12][13][14]. An overlap structure consisting of two ␥ variants is shown in Fig.…”

“…Another misunderstanding occurred during the study of ␥ ↔ ␣ 2 phase transformations. The structures of fringes (FR) were frequently observed between the ␥ and ␣ 2 phases [13,14]. These fringes were once considered as the stacking faults fringes, which promoted the progress of the ␥ ↔ ␣ 2 phase transformations.…”

A New Mechanism of Dynamic Phase Transformations in An Isothermal Forged Beta–Gamma Intermetallic Alloy

“…Then, the occurrence of γ → α 2 + B2 phase transition during heat treatment at 1000 °C is an abnormal phenomenon. During forging at high temperature, stress-induced phase transformation, mainly including γ → α 2 , α 2 → γ and α 2 → B2, will occur in the TiAl-based alloy [8,15,16]. In the (α + γ + β/B2) phase field, different strain amounts lead to different fractions of phases, and the fraction of γ phase increases with increasing strain at the same temperature [11,17].…”