Lamellar orientation control in a Ti–46Al–5Nb alloy by directional solidification

Lamellar microstructures of the Ti–46Al–5Nb alloy solidifying through the primary β phase were successfully aligned parallel to the growth direction by using the double directional solidification (DS) technique. The same growth conditions in both DS processes and the completion of the peritectic transformation in the dendritic regions are necessary for the primary β phase TiAl alloys to control the lamellar orientation.

Research highlights
► The directional solidification (DS) was performed twice to control the lamellar orientation.
► The lamellar microstructures were aligned parallel to the growth direction in primary ? TiAl alloys.
► The same growth conditions are needed in the two DS processes.
► The complete peritectic transformation is required in the dendritic regions.