Anisotropic in elasticity, sound velocity and minimum thermal conductivity of Al–Cu intermetallic compounds

Abstract First-principles calculations were utilized to study the anisotropic in terms of elasticity, sound velocity and minimum thermal conductivity of Al–Cu intermetallic compounds (AlCu, c-AlCu3, o-AlCu3, o-Al2Cu, t-Al2Cu, Al3Cu2 and Al4Cu9). There was good agreement between our calculated lattice constants and previous experimental and theoretical results. The compounds' anisotropy of elasticity was estimated. They had different anisotropic elastic properties. The anisotropy in sound velocity showed that the faster mixed mode (v+) is much greater than that of slower mixed mode (v-) and pure transverse mode (vt) for AlCu phase, while the sound velocity of pure longitudinal mode (vl) is the largest in cubic phase (c-AlCu3 and Al4Cu9), orthorhombic phase (o-AlCu3 and o-Al2Cu) and tetragonal phase (t-Al2Cu). The calculated minimum thermal conductivity of the compounds from the Clarke's model indicated that they had obvious anisotropy.