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Chen et al. J Mater Inf 2023;3:10 https://dx.doi.org/10.20517/jmi.2023.06 Page 3 of 19

Table 1. Pros and cons of the empirical methods for EHEA design
Methods Pros Cons
Simple mixing Take binary eutectics as the constituents, which can be (1) Lack of supportive physical and thermodynamic theories, which
method easily located from phase diagrams significantly reduces the efficiency
“LEGO” method
Pseudo-binary With the help of CALPHAD, a pseudo-binary system (2) The explorable space following empirical methods is limited
method can be quickly constructed and evaluated compared with the vast compositional space of HEAs
Grouping
method

Figure 1. The schematic for the various empirical design methods for eutectic high entropy alloys.

an avenue to locate EHEA compositions. In practice, one can add the weighted compositions of binary
eutectics as a candidate composition C for a multi-component alloy, which may be formulated as
eutectic
follows:

th
where C stands for the eutectic composition; A and B stand for the constituent element of the i binary
eutectic i i
eutectic, while x is the weighting factor. Following this line of reasoning, many EHEAs or multi-component
i [57] [60] [84]
eutectic compositions were discovered, including Nb CoCrFeNi , Nb Co Fe Ni , Nb CoFeNi
1.74
0.8
0.45
2.82
0.5
and Nb CoCrFeNi [85,86] , etc. Here we emphasized that the values of x are not fixed; however, in the
i
0.5
literature, they were mostly set equal or nearly equal in a heuristic manner such that the overall composition
was close to an equiatomic or near-equiatomic composition, as listed in Table 2.
Pseudo-binary eutectics [89,90] [91,92]
Since mixing of elements with a similar atomic size tends to form solid solutions , such as CoCrNi ,
[93]
[94]
CoCrFeNi , and CoCrFeNi , one alternative way to design EHEAs is to view these solid solutions as a
2