In situ observations of solidification in Ti–Al–Ta alloys by synchrotron radiation

In situ observations of phase transformations involving the melt are performed using energy-dispersive diffraction of synchrotron X-rays on electromagnetically levitated Ti–Al–Ta alloys. Determined solidification modes for various alloy compositions reveal an extension of β solidification phase field towards the Al-rich corner. These data have been assessed in a new thermodynamic description of the ternary Ti–Al–Ta system, which provides a reliable representation of the solid–liquid phase equilibria.