A comprehensive diffusion mobility database comprising 23 elements for magnesium alloys

• Published in: Acta materialia Vol. 201; no. C; pp. 191 - 208
• Main Authors: Zhong, Wei, Zhao, Ji-Cheng
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.12.2020; Elsevier
• Subjects: Atomic Mobility; Diffusion coefficients; Impurity diffusion coefficients; Magnesium alloys; Mobility database; Impurity diffusion coefficients; Atomic Mobility; Magnesium alloys; Diffusion coefficients; Mobility database
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2020.09.079

Reliable experimental diffusion coefficients of 10 key alloying elements in Mg obtained by the present authors together with experimental data in the literature enabled us to perform a systematic test of the reliability of diffusion coefficients obtained from DFT calculations. The computed activation energy values were found to be quite accurate (mostly within 0.2 eV) but the computed pre-factors were less reliable. Such insights allowed us to develop a practical and yet robust strategy to perform diffusion mobility assessments by adopting the computed activation energy while fitting only the pre-factor when available experimental data are limited to a narrow temperature range. The overall good agreement between the DFT data and experimental data also gave us the confidence to employ the computed data for those that were still missing or inaccessible from experimental measurements. A systematic assessment of both the measured and computed diffusion data in hcp Mg was performed using the above holistic approach to yield the most comprehensive open Mg mobility database to date, comprising 23 elements (Mg, Ag, Al, Be, Ca, Cd, Ce, Cu, Fe, Ga, Gd, In, La, Li, Mn, Nd, Ni, Pu, Sb, Sn, U, Y, Zn). This more reliable mobility database will contribute to future development of advanced Mg alloys. The holistic approach developed in this study will be very beneficial to the future establishment of reliable mobility databases for other alloy systems as well. [Display omitted]