Interface and strain energy driven variant selection in lamellar Ti-Al alloys.

The microstructure-property is essential important and complicated to be explored in metals. A novel multi-variant γ phase with nano-lamella incorporating multi-interface microstructure brings the special strength-ductility in Ti-Al alloys, the formation and selection of multi-variant interfaces are attractive questions. The phase-field simulations reveal the interface priority selection in the nucleation of γ variant with three kinds of interface, twin boundary (TB), pseudo-twin boundary (PTB) and ordered domain boundary (ODB), the low ratio of TB at nucleation stage transforms to the large ratio at growth stage, the interface elastic strain energy drives the γ variant selection.