**7. Computational approach in phase identification of magnesium containing high entropy alloys**

A large number of researches have been conducted on binary and ternary alloys but quaternary and quinary systems are yet to be explored. The number of possible HEAs are around 10<sup>177</sup> [59]. In order to screen out alloys for use, Calculation of Phase Diagrams (CALPHAD) is an exceptional tool. CALPHAD can be time consuming compared to Molecular Dynamics (MD) and Density Functional Theory (DFT) simulations. CALPHAD uses the phase diagrams and thermodynamics to determine the phases present in a new alloy. Although there is no database for Mg and Li containing HEAs due to insufficient amount of research published till date. There is need of First-principle DFT; MD simulation and Phase Field modelling to gain a better understanding of phases formation and understanding the factors that affects it.

Sanchez et al. used CALPHAD to predict phases present in Al60Cu10Fe10Cr5Mn5Ni5Mg5 alloy and found the Cu, Mg, Ni doped Al3Fe4, Al7Cu4Ni, Al8Mn5, D810 Al-Cr alloy phase and Mg2Cu6Al5 phases in the system [34]. The thermo-calc database successfully detected the phases present. Although, there are few discrepancies between the experimental results and Thermo-Calc calculations. CALPHAD predicted more constituent phases of which only few are reported by experiments. This suggests that despite having a slow cooling rate of solidification, total equilibrium state is not achieved in the manufacturing of the alloys. In general, this database has proven to be a good method for designing such HEAs [34].
