Stability criteria for nanocrystalline alloys
Author(s)
Kalidindi, Arvind Rama
Schuh, Christopher A
Date Issued
June 2017
Journal
Acta Materialia
Publisher
Elsevier BV
Citation
Kalidindi, Arvind and Christopher A. Schuh. "Stability criteria for nanocrystalline alloys." Acta Materialia 132 (June 2017): 128-137 © 2017 Acta Materialia Inc
Version
Author's final manuscript
Abstract
Alloying nanocrystalline materials to stabilize them against grain growth is proving a critical enabling strategy for the processing and usage of bulk nanocrystalline parts. Alloying elements that segregate strongly to grain boundaries can lead to a preference for nanocrystalline structure, and to be most stable the grain boundary segregated state would need to be preferred to forming any other phase or solute configuration, including a solid solution, ordered compounds, or solute precipitates. In this paper, a stability criterion is developed by comparing the enthalpy of the grain boundary segregated state against such stable bulk phases. This enthalpic criterion is also translated into a lattice model framework to enable the use of Monte Carlo simulations to incorporate entropic and geometric effects in assessing nanocrystalline stability. Monte Carlo simulations show that entropy can play a role in stabilizing nanocrystalline states, leading to duplex structures, and also in forming a grain boundary network preferentially over a disordered or amorphous-like bulk phase. Keywords: Nanocrystalline; Alloy; Grain boundary; Segregation; Intermetallic
MIT Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering
Terms of Use
Creative Commons Attribution-NonCommercial-NoDerivs License
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1016/j.actamat.2017.03.029
