%0 Journal Article
%T Composition-dependent apparent activation-energy and sluggish grain-growth in high entropy alloys
%A B. Gwalani
%A G. Thompson
%A R. Banerjee
%A R. Salloom
%A S. G. Srinivasan
%A S. G. Valentin
%A T. Alam
%A X. Zhou
%J Materials Research Letters
%D 2019
%R https://doi.org/10.1080/21663831.2019.1601644
%X ABSTRACT Experimental results reveal that the apparent activation-energy for grain-growth in an fcc-based AlxCoCrFeNi high entropy alloy (HEA) system increases from 179 to 486£¿kJ/mol when the Al content increases from x£¿=£¿0.1 to 0.3. These unexpectedly high apparent activation-energy values can be potentially attributed to solute clustering within the fcc solid-solution phase that develops with increasing Al content in this HEA. Detailed microstructural analysis using atom-probe tomography and density functional theory (DFT) calculations strongly indicate the presence of such nanoscale clusters. This phenomenon can change grain-growth from a classical solute-drag regime to a much more sluggish cluster-drag based mechanism in these HEAs. GRAPHICAL ABSTRACT IMPACT STATEMENT First report on a composition dependent change in apparent activation-energy for grain-growth in high entropy alloys. A novel cluster drag effect inhibiting grain-growth kinetics is suggested
%U https://www.tandfonline.com/doi/full/10.1080/21663831.2019.1601644