Dispersion strengthened high entropy alloys for extreme conditions
Project ID:GA17-23964S
Provider:Czech Science Foundation
Period:Jan 01, 2017 - Dec 31, 2019
Recipient -- coordinator:Institute of Physics of Materials of the CAS, v. v. i. -- Ing. Hynek Hadraba, Ph.D.
Co-recepient(s) / PI(s):Institute of Plasma Physics, Czech Academy of Sciences, Prague -- Ing. Jiří Matějíček, Ph.D.
Co-investigators from IPPM. Vilémová, B. Nevrlá, K. Illková, F. Lukáč

Aims of the project: Conventional metallic alloys are usually based on one principal element and alloying elements are added to improve its properties. On the contrary, the concept of high-entropy alloys is based on multiple principal elements in roughly equal proportions. The high configuration entropy of the alloy overcome enthalpies of compounds formation and phase separation. Selected reference CoCrFeNiMn high-entropy alloy has simple microstructure exhibiting promising properties at high as well as at cryogenic temperatures. At high temperatures strength of this high-entropy alloy substantially decreases due to weakening of the pinning effect of distorted lattice. Main aim of the project is to enhance high temperature resistance via introducing nano-sized particles to the microstructure by mechanical alloying. Secondary particles pinning effect can overcome the strength drop at high temperatures and can enhance creep behaviour. Second goal will be modification of chemical composition using low-activation elements suitable for irradiation at high temperatures keeping superior mechanical properties.

Results:

Vilémová M., Illková K., Lukáč F., Matějíček J., Klečka J., Leitner J.: Microstructure and phase stability of W-Cr alloy prepared by spark plasma sintering. Fusion Engineering and Design 127 [February] (2018) 173-178. [ Abstract ] [ Link ]

Dobeš F., Hadraba H., Chlup Z., Dlouhý A., Vilémová M., Matějíček J.: Compressive creep behavior of an oxide-dispersion-strengthened CoCrFeMnNi high-entropy alloy. Materials Science and Engineering A-Structural materials 732 [AUG] (2018) 99-104. [ Abstract ] [ Link ]