Microstructural and Elastic Properties of Stable Aluminium-rich TiAl and TiAl2 Formed Phase Intermetallics

Abstract : We studied aluminium-rich Ti-Al (Ti32Al68 and Ti40Al60) binary alloys that were composed of TiAl and TiAl2 lamellar microstructures. The law of mixtures was employed in calculating the theoretical Young’s moduli. The lattice parameters of the alloys showed that both were tetragonal crystals. In the computational study, we made use of our modified method for the stress–strain calculation of elastic constants. The alloys at the respective chemical compositions were modelled by creating titanium (Ti) supercells, which were then doped by replacing some of the Ti atoms with aluminium atoms. The values of elastic moduli were verified by the ab initio calculation in this work, which showed a perfect agreement. The Pugh’s ratio showed that both the alloys are ductile.