A closely-complete peritectic transformation during directional solidification of a Ti-45Al-8.5Nb alloy

A closely-complete peritectic transformation (PT) was found during directional solidification (DS) of a Ti-45Al-8.5Nb alloy under a low temperature gradient. The closely-complete PT can align the peritectic α phase and control the lamellar orientation. The conditions to obtain a complete PT in primary β TiAl alloys were theoretically evaluated in the dendrite regime. ► A Ti-45Al-8.5Nb alloy was directionally solidified under a low temperature gradient. ► The peritectic transformation was closely completed during the directional solidification. ► The complete transformation can control the peritectic α phase and align the lamellar orientation. ► The conditions to achieve it in primary β TiAl alloys were addressed in the dendrite regime.