DOI: 10.5281/zenodo.5155150
title: Materials for Design Open Repository. High Entropy Alloys

description: The current dataset is composed of a collection of High Entropy Alloys (HEAs). It contains the alloy composition, the number of chemical elements (No), the phase in a simple form (S_Phase), where 4 classes of phases were considered, namely amorphous (AM), intermetallic (IM), solid solution (SS), and solid solution + intermetallic (SS+IM). It contains also a second phase column (Phase), where we added the type of phase present in alloys with SS and repeated the S_Phase entry for the other cases. We have calculated 13 design parameters (see their definition below) used to design HEAs, known as the parametric approach. Finally, a set of columns containing the chemical elements and their corresponding fraction in the alloy is included. This dataset was developed in the framework of the European project ACHIEF for the discovery of novel materials to be used in industrial processes. Mean atomic radius <em>a</em> (Å) \(a = \displaystyle\sum_{i=1}^{n} c_i r_i\) Atomic size difference δ \(\delta = \sqrt{\displaystyle\sum_{i=1}^{n} c_i \bigg(1 - \dfrac{r_i}{a} \bigg)^2}\) Average melting temperature <em>T<sub>m</sub></em> (K) \(T_m = \displaystyle\sum_{i=1}^{n} c_i T_{mi}\) Average melting temperature standard deviation (K) \(\sigma_{T_m} = \sqrt{\displaystyle\sum_{i=1}^{n} c_i \bigg(1 - \dfrac{T_{mi}}{T_m} \bigg)^2}\) Mixing enthalpy Δ<em>H<sub>mix</sub></em> (kJ/mol) \(\Delta H_{mix} = 4 \displaystyle\sum_{i \neq j} c_i c_j H_{ij}\) Mixing enthalpy standard deviation (kJ/mol) \(\sigma_{\Delta H_{mix}} = \sqrt{\displaystyle\sum_{i \neq j} c_i c_j (H_{ij} - \Delta H_{mix})^2}\) Ideal mixing entropy <em>S<sub>id</sub></em> (<em>R</em>)<strong>*</strong> \(S_{id} = \Delta S_{mix} = -R \displaystyle\sum_{i=1}^{n} c_i \ln c_i\) Electronegativity <em>χ</em> \(\chi = \displaystyle\sum_{i=1}^{n} c_i \chi_i\) Electronegativity difference in a multi-component alloy system \(\Delta\chi = \displaystyle\sqrt{\sum_{i=1}^{n} c_i(\chi_i - \chi)^2}\) Valence electron concentration <em>VEC</em> \(VEC = \displaystyle\sum_{i=1}^{n} c_i \cdot VEC_i\) Valence electron concentration standard deviation \(\sigma_{VEC} = \sqrt{\displaystyle\sum_{i=1}^{n} c_i (VEC_i - VEC)^2}\) Mean bulk modulus <em>K </em>(GPa) \(K = \displaystyle\sum_{i=1}^{n} c_i K_i\) Bulk modulus standard deviation (GPa) \(\sigma_{K} = \sqrt{\displaystyle\sum_{i=1}^{n} c_i (K_i - K)^2}\) where <em>n</em> is the number of components in the alloy system, <em>c<sub>i</sub></em> is the stoichiometric ratio, <em>r<sub>i</sub></em> is the atomic radius, <em>T<sub>mi</sub></em> is the melting temperature, <em>χ<sub>i</sub></em> is the Pauli electronegativity, <em>VEC<sub>i</sub></em> is the valence electron concentration, and <em>K<sub>i</sub></em> is the bulk modulus for the <em>i</em>-th component of the alloy. <em>H<sub>ij</sub></em> is the binary mixing enthalpy in the liquid phase, and <em>R</em> is the gas constant. <strong>*Note:</strong> the ideal mixing entropy <em>S<sub>id</sub></em> units in the dataset appears as kJ/mol, but they should be written in terms of the gas constant <em>R</em>, e.g., the compound Ag<sub>2</sub>Al has <em>S<sub>id</sub></em> = 0.636 <em>R</em>, where <em>R</em> = 8.314 J · K<sup>−1</sup> · mol<sup>−1</sup>.