Concentration-dependent atomic mobilities in FCC CoCrFeMnNi high-entropy alloys

Autor: Esin, Vladimir A., Gaertner, Daniel, Abrahams, Katrin, Kottke, Josua, Esin, Vladimir, Steinbach, Ingo, Wilde, Gerhard, Divinski, Sergiy
Přispěvatelé: Centre des Matériaux (MAT), MINES ParisTech - École nationale supérieure des mines de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), UMR 212 EME 'écosystèmes marins exploités' (EME), Institut de Recherche pour le Développement (IRD)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Montpellier (UM), Interdisciplinary Centre for Advanced Materials Simulation (ICAMS), Ruhr-Universität Bochum [Bochum], Institute of Materials Physics, Westfälische Wilhelms-Universität Münster (WWU)
Rok vydání: 2019
Předmět:
Zdroj: Acta Materialia
Acta Materialia, Elsevier, 2019, 166, pp.357-370. ⟨10.1016/j.actamat.2018.12.033⟩
ISSN: 1359-6454
DOI: 10.1016/j.actamat.2018.12.033
Popis: The diffusion kinetics in a CoCrFeMnNi high entropy alloy is investigated by a combined radiotracer--interdiffusion experiment applied to a pseudo-binary Co$_{15}$Cr$_{20}$Fe$_{20}$Mn$_{20}$Ni$_{25}$ / Co$_{25}$Cr$_{20}$Fe$_{20}$Mn$_{20}$Ni$_{15}$ couple. As a result, the composition-dependent tracer diffusion coefficients of Co, Cr, Fe and Mn are determined. The elements are characterized by significantly different diffusion rates, with Mn being the fastest element and Co being the slowest one. The elements having originally equiatomic concentration through the diffusion couple are found to reveal up-hill diffusion, especially Cr and Mn. The atomic mobility of Co seems to follow an S-shaped concentration dependence along the diffusion path. The experimentally measured kinetic data are checked against the existing CALPHAD-type databases. In order to ensure a consistent treatment of tracer and chemical diffusion a generalized symmetrized continuum approach for multi-component interdiffusion is proposed. Both, tracer and chemical diffusion concentration profiles are simulated and compared to the measurements. By using the measured tracer diffusion coefficients the chemical profiles can be described, almost perfectly, including up-hill diffusion.
15 pages, 7 figures
Databáze: OpenAIRE