Stress-driven grain refinement in a microstructurally stable nanocrystalline binary alloy

KA Darling and S Srinivasan and RK Koju and BC Hornbuckle and J Smeltzer and Y Mishin and KN Solanki, SCRIPTA MATERIALIA, 191, 185-190 (2021).

DOI: 10.1016/j.scriptamat.2020.09.041

Deformation-induced grain-growth in nanocrystalline materials is a widely-reported phenomenon that has been attributed to grain boundary (GB) processes. In this paper, we report on the opposite phenomenon, wherein a stable nanocrystalline (NC) Cu-Ta alloy undergoes a further refinement of the nanograins during severe plastic deformation (SPD). SPD up to 250% results in a significant grain-size reduction despite the 350 degrees C increase in temperature caused by the deformation process. Experiments and atomistic-simulations show that this unexpected grain- refinement is a direct result of well-dispersed Ta-nanoclusters throughout grain centers and along GBs acting as kinetic-pinning agents and suppressing GB processes that occur during recrystallization. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Return to Publications page