Temperature-dependent structural, mechanical, and thermodynamic properties of B2-phase Ti2AlNb for aerospace applications

Abstract

Ti2AlNb intermetallic is a potential substitute for Ni-based superalloys in nextgeneration aerospace materials. In the current work, the structural, mechanical, and thermodynamic properties of the Ti2AlNb in B2 phase are studied at various temperatures by implementing first principle calculations under quasiharmonic approximations. The lattice parameter, elastic moduli, and linear coefficient of thermal expansion (CTE) are well reproduced according to the experimental reports. The intermetallic remains mechanically and dynamically stable at all temperatures. The elastic moduli and microhardness decrease slightly from 0 to 1300 K. Furthermore, the calculations reveal that Ti2AlNb remains ductile at all temperatures. Phonon calculations show that Nb atoms are dominant contributor to the vibrational modes. The temperature-dependent heat capacities, entropy, CTE, and isothermal bulk modulus are further investigated. Present calculations predict that the B2 phase Ti2AlNb is a suitable candidate for the manufacturing of hig