High Entropy Alloys (HEA)

© [4]
Overview of typical values for fracture toughness and yield strength of several material classes

Lighter, stronger, more flexible, more wear and heat resistant are only some of the properties that are essential for materials these days. A systematic development of new materials is crucial to meet the constantly increasing requirements.

A completely new type of materials are High Entropy Alloys (HEAs). These multicomponent alloys consist mostly of a (near-) equimolar mixture of several different elements, e. g. CoCrFeMnNi [1, 2]. To further adjust the resulting properties, additional alloying elements with smaller content can be added, e. g. Aluminium in Al0.1CoCrFeMnNi. Despite their unconventional composition, HEAs show a rather simple microstructure, which consists mostly of one or more solid solution phases, and show interesting properties, as for example [1-3]:

  • High strength and ductility
  • Good high temperature behaviour
  • Low temperature ductility
  • Good wear resistance

R&D expertise

EBSD-Mapping von CoCrFeMnNi farbkodiert gemäß inverser Polfigur
© Fraunhofer IFAM Dresden
EBSD-mapping of CoCrFeMnNi colour-coded corresponding to inversed pole figure
© Fraunhofer IFAM Dresden
TEM-picture of precipitation hardened CoCrFeMnNiTi-HEA. A homogeneous matrix phase precipitates containing Ti is visible

Material Development

  • Alloy design according to request


Manufacturing Methods

  • Powder: application of pre-alloyed powder or mechanical alloying and mixing of elemental powders
  • Compaction: different methods, e.g. hot pressing, Spark Plasma Sintering, Selective Electron Beam Melting
  • Post treatment: heat treatment etc.


  • Accredited laboratory for mechanical analysis, thermal analysis and for powder analysis
  • Friction and wear test
  • Mechanical properties (e.g. density and microstructure)
  • Characterisation of functional properties, as for example electrical resistivity

Customer benefits

REM-BSE-Aufnahmen von AlMo0,5CrFeNi (+ Y)
© Fraunhofer IFAM Dresden
SEM picture of AlMo0,5CrFeNi (+ Y)

The automotive and aviation industry, mechanical engineering and construction industry have one thing in common: the urgent demand for innovative materials. As materials are also significantly involved in technical progress, they have in nearly all branches of industry a key role. Up to 70 % of all new products are predicated on material development [5].

High-entropy alloys are a highly suitable possibility to realise a completely new alloying concept and receive appropriate properties and property combinations.

Possible applications for HEAs are e.g. [1-3]:

  • Refractory HEAs or precipitation hardened HEAs for high-temperature applications, e.g. furnace parts or grits
  • Coating for biomedical applications
  • Binder phase for composites
  • HEAs as irradiation protection against ion radiation
  • Wear resistant HEAs as protective coating
  • HEAs for cryogenic applications in food industry or liquid gas tanks


N. Eißmann, B. Klöden, T. Weißgärber, B. Kieback: „High-entropy alloy CoCrFeMnNi produced by powder metallurgy“, Powder Metallurgy, Jg. 60, Nr. 3, 2017, 184–197



[1] J.-W. Yeh et al., “Nanostructured High-Entropy Alloys with Multiple Principal Elements: Novel Alloy Design Concepts and Outcomes,” Advanced Engineering Materials, vol. 6, no. 5, pp. 299–303, 2004.

[2] J. W. Yeh, Y. L. Chen, S. J. Lin, and S. K. Chen, “High-Entropy Alloys – A New Era of Exploitation,” Materials Science Forum, vol. 560, pp. 1–9, 2007.

[3] M. C. Gao, J.-W. Yeh, and P. K. Liaw, High-entropy alloys: Fundamentals and applications. Cham: Springer International Publishing, 2016.

[4] B. Gludovatz et al., “A fracture-resistant high-entropy alloy for cryogenic applications,” Science, vol. 345, no. 6201, pp. 1153–1158, 2014.

[5] Bundesministerium für Bildung und Forschung, “Vom Material zur Innovation: Rahmenprogramm zur Förderung der Materialforschung,” 2015. [Online] Available: https://www.werkstofftechnologien.de/programm/. Accessed on: Jun. 12 2019