An In Situ High?Energy Synchrotron X?Ray Diffraction Study of Directional Solidification in Binary TiAl Alloys

Phase formation and microstructure selection during solidification in ?-TiAl alloys are highly relevant, both with respect to the texture of cast directional solidification, which allows obtain a unique combination properties. However, cooling room temperature, solidifying phases transform low-temperature phases, mask prior situation solidification. A new inductive crucible-free zone melting furnace is used this work, specially designed for situ investigations using synchrotron radiation. Herein, 45 48 at% Al studied, it can be shown that varying withdrawal rate, change from ? synchronous ? + occurs Ti–48Al, as predicted literature. Furthermore, observed by increasing preferred <001> growth phase Al, interpreted transition dendritic The observations compared map calculated according nucleation constitutional undercooling (NCU) model proposed