First-principles calculations of binary Al compounds: Enthalpies of formation and elastic properties

Systematic first-principles calculations of energy vs. volume (E–V) and single crystal elastic stiffness constants ( c i j ’s) have been performed for 50 Al binary compounds in the Al–X (X = Co, Cu, Hf, Mg, Mn, Ni, Sr, V, Ti, Y, and Zr) systems. The E–V equations of state are fitted by a four-parameter Birch–Murnaghan equation, and the c i j ’s are determined by an efficient strain–stress method. The calculated lattice parameters, enthalpies of formation, and c i j ’s of these binary compounds are compared with the available experimental data in the literature. In addition, elastic properties of polycrystalline aggregates including bulk modulus (B), shear modulus (G), Young’s modulus (E), B/G (bulk/shear) ratio, and anisotropy ratio are calculated and compared with the experimental and theoretical results available in the literature. The systematic predictions of elastic properties and enthalpies of formation for Al–X compounds provide an insight into the understanding and design of Al-based alloys.