Modified embedded atom method potential for Fe-Al intermetallics mechanical strength: A comparative analysis of atomistic simulations

The structural and mechanical properties of Fe-Al compounds (FeAl, FeAl, FeAl, FeAl, FeAl, FeAl) have been studied using modified embedded atom method (MEAM) potentials. The equilibrium lattice constants, formation enthalpies, and elastic properties have been investigated and compared with other studies. The calculated lattice constants show good agreement with the embedded atom method (EAM) and density functional theory (DFT) calculations and with experiments. All Fe-Al compounds are mechanically stable according to the elastic constants restrictions. The calculated bulk modulus of the compounds does not show a linear relation with Fe concentration, which is most probably caused by the mechanical anisotropy of Fe-Al compounds. However, comparison of the Fe-Al mechanical properties of MEAM, DFT and EAM-based approaches and experiments show non-consistent differences, which reflects uncertainties with several of these methods, due to assumptions and simplifications imposed during calculations. In general, DFT calculations are closer to experimental observations than semi-empirical potentials. Comprehensive comparisons are made based on theoretical and experimental methodologies.