About the TCS High Entropy Alloys Database (TCHEA)

TCS High Entropy Alloys Database (TCHEA) is a thermodynamic database for high entropy alloys (HEA) [2004Yeh; 2006Yeh]. HEAs are a new class of materials consisting of more than one principal element in a multi-component system. They are also known as multi-principal element alloys (MPEAs) [2013Wan; 2015Sen] or complex concentrated alloys (CCAs). The coupling of our CALPHAD based computational tools and databases allows a high fidelity calculation of thermodynamic properties and phase equilibria in multi-component HEAs, thus shedding light on the formation mechanism and thermodynamic and kinetic stability of HEAs, providing an efficient way to design HEAs for desired materials properties based on the prediction of microstructures through process optimization.

In addition to thermodynamic data, the database has thermophysical and elastic properties data available for:

  • Molar volume with thermal expansion coefficients
  • Viscosity of the metallic liquids
  • Surface tension of liquid metallic alloys
  • Electrical resistivity
  • Thermal conductivity
  • Elastic moduli and elastic constants

TCHEA8 Thermophysical and Elastic Properties

The database can be used with other products: Thermo-Calc, the Add-on Diffusion Module (DICTRA), Precipitation Module (TC-PRISMA), and/or Additive Manufacturing (AM) Module, and all available SDKs.

The thermodynamic database is compatible with the corresponding TCS High Entropy Alloy Mobility Database (MOBHEA) that provides kinetic data for those working with the add-on kinetic modules – the Diffusion Module (DICTRA) and the Precipitation Module (TC-PRISMA) – as well as a few specific calculation types, such as Scheil with back diffusion. The current version of the mobility database is MOBHEA3.

There are examples available to both demonstrate the validation of the database and to showcase the types of calculations that can be used for different materials or application area.

About the Database Examples

Some case examples of how the TCHEA8 database can be used include:

  • Calculate various phase diagrams and property diagrams in the assessed systems and higher-order systems.
  • Predict solidification behavior of HEAs with a Scheil-Gulliver calculation.
  • Predict a wide variety of equilibrium properties such as phase amount and constitution as a function of composition or temperature, homogeneity range, or thermo-stability of HEAs.
  • Study the oxidation behaviors of HEAs at various temperatures and compositions.
  • Use the Add-on Diffusion Module (DICTRA) and combine it with TCHEA and compatible kinetic databases to simulate typical diffusion-controlled phase transformations in HEAs under arbitrary heat treatment conditions.
  • Use the Precipitation Module (TC-PRISMA) and combine it with TCHEA and compatible kinetic databases, to simulate the concurrent nucleation, growth and coarsening of precipitates.

It is possible to combine several databases to make calculations using Thermo‑Calc. For more information related to a specific type of problem, contact one of our support specialists at info@thermocalc.com. The experts are available to make recommendations on the most suitable database to use for your needs.

TCHEA: TCS High Entropy Alloys Database Revision History. The current version of the database is TCHEA8. See the link for any subversion release details.

[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 (2004) 213–218.

[2004Yeh] J. W. Yeh, S. K. Chen, S. K. Lin, J. Y. Gan, T. S. Chin, T. T. Shun, C. H. Tsau, S. Y. Chang, Nanostructured High-Entropy Alloys with Multiple Principal Elements: Novel Alloy Design Concepts and Outcomes. Adv. Eng. Mater. 6, 299–303 (2004).

[2006Yeh] J.-W. Yeh, Recent progress in high-entropy alloys. Ann. Chim. Sci. des Matériaux. 31, 633–648 (2006).

[2013Wan] S. Wang, Atomic Structure Modeling of Multi-Principal-Element Alloys by the Principle of Maximum Entropy. Entropy. 15, 5536–5548 (2013).

[2015Sen] O. N. Senkov, J. D. Miller, D. B. Miracle, C. Woodward, Accelerated exploration of multi-principal element alloys with solid solution phases. Nat. Commun. 6, 6529 (2015).

[2017Mir] D.B. Miracle, O.N. Senkov, A critical review of high entropy alloys and related concepts, Acta Mater. 122 (2017) 448–511.

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

[2018Chen] H.-L. Chen, H. Mao, Q. Chen, Database development and Calphad calculations for high entropy alloys: Challenges, strategies, and tips. Mater. Chem. Phys. 210 (2018) 279-290.