The role of confinement on stress-driven grain boundary motion in nanocrystalline aluminum thin films

TR Number
Date
2012-12-15
Journal Title
Journal ISSN
Volume Title
Publisher
American Institute of Physics
Abstract

3D molecular dynamics simulations are performed to investigate the role of microstructural confinement on room temperature stress-driven grain boundary (GB) motion for a general population of GBs in nanocrystalline Al thin films. Detailed analysis and comparison with experimental results reveal how coupled GB migration and GB sliding are manifested in realistic nanoscale networks of GBs. The proximity of free surfaces to GBs plays a significant role in their mobility and results in unique surface topography evolution. We highlight the effects of microstructural features, such as triple junctions, as constraints to otherwise uninhibited GB motion. We also study the pinning effects of impurities segregated to GBs that hinder their motion. Finally, the implications of GB motion as a deformation mechanism governing the mechanical behavior of nanocrystalline materials are discussed. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4770357]

Description
Keywords
Free surfaces, Thin film growth, Molecular dynamics, Topography, Thin film structure
Citation
Gianola, Daniel S., Farkas, Diana, Gamarra, Martin, He, Mo-rigen (2012). The role of confinement on stress-driven grain boundary motion in nanocrystalline aluminum thin films. Journal of Applied Physics, 112(12). doi: 10.1063/1.4770357