FCC Medium (MEA) and High Entropy (HEA) Alloys

These examples show some classical calculations of the equilibrium phase stabilities for the FCC medium entropy (MEA) and high entropy (HEA) alloys when using the TCS High Entropy Alloys Database (TCHEA).

CoCrFeNi FCC MEA

$Mole fraction of equilibrium phases at various temperatures in the CoCrFeNi equiatomic alloy$

Figure 1: Mole fraction of equilibrium phases at various temperatures in the CoCrFeNi equiatomic alloy [2017Mao].

CoCrFeMnNi FCC HEA

$Mole fraction of equilibrium phases at various temperatures in the CoCrFeMnNi equiatomic alloy.$

Figure 2: Mole fraction of equilibrium phases at various temperatures in the CoCrFeMnNi equiatomic alloy, a.k.a. the Cantor alloy [2004Can] .

Co_x(CrFeMnNi)_100-x FCC HEA

TCS High Entropy Alloys Database (TCHEA) predicts well the melting properties (solidus and liquidus), and stability range of FCC, BCC, sigma, and L1₀ phases.

Figure 3: Calculated phase equilibria in the isopleth of Cox(CrFeMnNi)_100-x, where x represents at% of Co. In the plot, symbols represent experimentally observed phases. These are coded in color for different phase assemblages, e.g. green for single FCC, and red for FCC+Sigma two-phase coexists. Different symbols represent different experimental work. Filled and empty symbols stand for long (>=24 h) and short (<24 h) annealing, respectively.

CoCrCu_xFeNi FCC HEA

Figure 4: Calculated phase equilibria in the isopleth for the series of the CoCrCu_xFeNi quinary alloys, where x=0-1 represents moles of Cu atoms [2017Mao].

References

[2004Can] B. Cantor, I. T. H. Chang, P. Knight, A. J. B. Vincent, Microstructural development in equiatomic multicomponent alloys. Mater. Sci. Eng. A. 375–377, 213–218 (2004).

[2017Mao] H. Mao, H.-L. Chen, Q. Chen, TCHEA1: A Thermodynamic Database Not Limited for “High Entropy” Alloys. J. Phase Equilibria Diffus. 38, 353–368 (2017).