Intermetallic γ-TiAl based alloys exhibit excellent high-temperature strength combined with low density. This makes them ideal candidates for replacing the twice as dense Ni base super-alloys, currently used in the medium temperature range (~700 °C) of industrial and aviation gas turbines. An important step towards the serial production of TiAl parts is the development of suitable hot-forming processes. Thermo-mechanical treatments often result in mechanical anisotropy due to the formation of crystallographic textures. However, with conventional texture analysis techniques, their formation can only be studied after processing. In this study, in situ high-energy X-ray diffraction measurements with synchrotron radiation were performed during hot-forming. Thus, it was possible to record the evolution of the phase constitution as well as the formation of crystallographic texture of different phases directly during processing. Several process temperatures (1100 °C to 1300 °C) and deformation rates were investigated. Based on these experiments, a process window can be recommended which results in the formation of an optimal reduced texture.

Phase formation and microstructure selection during solidification in γ‐TiAl alloys are highly relevant, both with respect to the microstructure and texture of cast alloys and to directional solidification, which allows to obtain a unique combination of properties. However, during cooling to room temperature, the solidifying phases transform to low‐temperature phases, which mask the prior situation during solidification. A new inductive crucible‐free zone melting furnace is used in this work, which is specially designed for in situ investigations of solidification using synchrotron radiation. Herein, alloys with 45 and 48 at% Al are studied, and it can be shown that with varying withdrawal rate, a change from α solidification to synchronous β + α solidification occurs in Ti–48Al, as it is predicted in the literature. Furthermore, it is observed that by increasing the withdrawal rate, a preferred growth of the β phase occurs in alloys with 45 at% Al, which is interpreted as a transition to dendritic solidification. The observations are compared with a microstructure selection map calculated according to the nucleation and constitutional undercooling (NCU) model proposed in the literature.