Institute of Physics of Materials AS CR, v. v. i. > Projects > Dispersion strengthened high entropy alloys for extreme conditions

Dispersion strengthened high entropy alloys for extreme conditions

InvestigatorIng. Hynek Hadraba, Ph.D.
Number of Project17-23964S
AgencyGrantová agentura České republiky
Duration2016-12-31 - 2019-12-30

Anotace
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.


2020

Vilémová M., Hadraba H., Weiss Z., Lukáč F., Csáki Š., Chlup Z., Matějíček J., Chráska T.: Phase, Composition and Structure Changes of CoCrNi-Based Concentrated Alloys Resulting from High Temperature Oxidation. Materials 13 (2020) 2276

Moravčík I., Hadraba H., Li L., Dlouhý I., Raabe D., Li Z.: Yield strength increase of a CoCrNi medium entropy alloy by interstitial nitrogen doping at maintained ductility. Scr. Mater. 178 (2020) 391-397

Šiška F., Čech J., Haušild P., Hadraba H., Chlup Z., Husák R., Stratil L.: Twinning in CoCrFeNiMn high entropy alloy induced by nanoindentation. Mater. Sci. Eng. A 784 (2020) 139297



2019

Chlup Z., Fintová S., Hadraba H., Kuběna I., Vilémová M., Matějíček J.: Fatigue Behaviour and Crack Initiation in CoCrFeNiMn High-Entropy Alloy Processed by Powder Metallurgy. Metals 9 (2019) 1-12

Husák R., Hadraba H., Chlup Z., Heczko M., Kruml T., Puchý V.: ODS EUROFER Steel Strengthened by Y-(Ce, Hf, La, Sc, and Zr) Complex Oxides. Metals 9 (2019) 1148



2018

Dobeš F., Hadraba H., Chlup Z., Dlouhý A., Vilémová M., Matějíček J.: Compressive creep behavior of an oxide-dispersion-strengthened CoCrFeMnNi high-entropy alloy. Mater. Sci. Eng. A 732 (2018) 99-104



2017

Moravčík I., Čížek J., Kováčová Z., Nejezchlebová J., Kitzmantel E., Neubauer E., Kuběna I., Horník V., Dlouhý I.: Mechanical and Microstructural Characterization of Powder Metallurgy CoCrNi Medium Entropy Alloy. Mater. Sci. Eng. A 701 (2017) 370-380