Compressive creep behavior of an oxide-dispersion-strengthened CoCrFeMnNi high-entropy alloy

0495933 - ÚFM 2019 RIV CH eng J - Journal Article
Dobeš, Ferdinand - Hadraba, Hynek - Chlup, Zdeněk - Dlouhý, Antonín - Vilémová, Monika - Matějíček, Jiří
Compressive creep behavior of an oxide-dispersion-strengthened CoCrFeMnNi high-entropy alloy.
Materials Science and Engineering A Structural Materials Properties Microstructure and Processing. Roč. 732, AUG (2018), s. 99-104. ISSN 0921-5093. E-ISSN 1873-4936
R&D Projects: GA ČR(CZ) GA17-23964S
Institutional support: RVO:68081723 ; RVO:61389021
Keywords : superplasticity * temperatures * diffusion * model * flow * High-entropy alloy * Oxide dispersion strengthened alloy * Creep * Mechanical alloying * Powder metallurgy * Spark plasma sintering
OECD category: Condensed matter physics (including formerly solid state physics, supercond.); Condensed matter physics (including formerly solid state physics, supercond.) (UFP-V)
Impact factor: 4.081, year: 2018

Creep tests of two equiatomic CoCrFeMnNi alloys were conducted in the temperature range from 973 K to 1073 K. The alloys were prepared by milling blends of powders of pure elements in a planetary ball mill and compacting by the spark plasma technique. Two variants of the alloys were prepared: (i) without and (ii) with the dispersion of oxides. Creep resistance was substantially improved by the presence of oxides. Diffusion creep controlled by lattice diffusion was suggested as a possible mechanism at low stresses. The effective diffusion coefficient calculated for Nabarro-Herring creep was comparable to the lattice diffusion coefficient of Ni in the same high-entropy alloy. At high stresses, the creep behavior was characterized by the presence of a threshold stress invoked by oxide particles.
Permanent Link: http://hdl.handle.net/11104/0288970