Prediction of heat-resistant Al–Fe–Cu–Zr alloy from first-principles calculations: Stoichiometries, electronic structure, and physical properties

Abstract

To investigate the effect of Zr on the properties of the Al–Fe–Cu system, the structural stability, electronic structure, and thermodynamic properties of the Al3Zr, Al6Fe, Al2Cu, and Al7FeCu2 phases were calculated and analyzed using the plane wave pseudo-potential method based on the first principles calculation. The results show that the addition of Zr can improve the thermal stability and melting point of aluminum alloy cables, but has a limit on the mechanical properties. Compared with Al6Fe, Al2Cu, and Al7FeCu2, Al3Zr exhibits better alloying ability and structural stability at 0 K. By comparing the density of states (DOS) and the number of transferred electrons, it is found that the Al3Zr phase has strong covalent bond characteristics. The elastic constants of Al3Zr, Al6Fe, Al2Cu, and Al7FeCu2 are calculated. It is found that the anisotropy of Al3Zr and Al7FeCu2 is small, and the mechanical properties of Al6Fe and Al2Cu are brittle, while the mechanical properties of Al6Fe and Al2Cu are plastic. According to the empirical formula, Al3Zr has the highest microhardness and melting point. In addition, it is found that the Al3Zr phase has the best thermal stability by thermodynamic analysis. The good thermal stability of Al3Zr was verified. In conclusion, this paper provides a theoretical basis for the thermodynamic optimization of the heat-resistant alloy Al–Fe–Cu–Zr series.