First principles study of Ti5Si3 intermetallic compounds with Cu additions: Elastic properties and electronic structure

Abstract

The structural stabilities, elastic and electronic properties of Ti5Si3 intermetallic compounds with Cu additions have been studied by density functional theory. The calculated lattice constants (a, c) and the equilibrium volume are found to decrease with the increasing of Cu atomic number.Then the independent elastic constants are calculated, the results shows that all the elastic constants of compounds satisfy the mechanical stability criteria, which indicates all these hexagonal structures are mechanically stable, furthermore, the elastic constants (C11, C44 and C66) decrease with the increasing of Cu atomic number. The calculated bulk modulus B, shear modulus G and Young’s modulus E decrease, while Poisson’s ratio σ and Cauchy pressure increase with the increasing of Cu atomic number, and the ductility is slightly improved. The calculated DOS showed that the density of states (DOSs) of the Feimi level increases and the stability of compounds decreases with the increasing of Cu atomic number.