TITLE

Model experiments for direct visualization of grain boundary deformation in nanocrystalline metals

AUTHOR(S)
Van VIiet, Krystyn J.; Tsikata, Sedina; Suresh, Subra
PUB. DATE
August 2003
SOURCE
Applied Physics Letters;8/18/2003, Vol. 83 Issue 7, p1441
SOURCE TYPE
Academic Journal
DOC. TYPE
Article
ABSTRACT
Recent experimental studies on nanocrystalline metals have shown that mechanical strength may decrease with decreasing grain size d for d<10–15 nm. The mechanisms underlying this trend are not understood, although such a relationship is in distinct contrast to that seen in microcrystalline metals whereby strength increases with decreasing grain size. Here, we present direct experimental observations of deformation via the bubble raft model, a two-dimensional analog to fcc crystals. We adopt nanoindentation as a means to introduce localized deformation, and quantify critical conditions for defect nucleation. We identify a transitional d of approximately 7 nm, at which further grain refinement leads to a decrease in the stress required to initiate plastic deformation. Further, we observe a concurrent transition in the primary deformation mechanism from discrete dislocation emission from grain boundaries (d>7 nm) to localized grain boundary migration (d<7 nm). Thus, these data suggest that both the onset and mechanisms of plasticity in nanocrystalline materials change markedly below a critical grain size. © 2003 American Institute of Physics.
ACCESSION #
10543211

 

Related Articles

  • A prototypical model of a dislocation source capable of generating shear band structures in crystalline solids during shock or impact. Coffey, C. S. // Journal of Applied Physics;8/15/1989, Vol. 66 Issue 4, p1654 

    Investigates the response of crystalline solids to high rate loading by shock or impact determined by the formation of shear band structures and the subsequent response of the localized structures to the applied stress. Maximum dislocation rate of the source; Rate of generation of dislocations;...

  • Grain boundaries and growth kinetics of polycrystalline ferrimagnetic oxides with chemical... Cho, Yong S.; Hoelzer, David T. // Journal of Applied Physics;4/15/1999 Part 2A of 2, Vol. 85 Issue 8, p5220 

    Presents information on a study which investigated the grain boundaries and grain growth kinetics of ferrimagnetic oxides modified by a sol-gel particulate coating process. Experimental details; Results and discussion; Conclusions.

  • Overcoming weak links at grain boundaries in Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub x] thick films.... Funahashi, Ryoji; Matsubara, Ichiro // Applied Physics Letters;6/17/1996, Vol. 68 Issue 25, p3629 

    Examines the grain boundaries in Bi[sub 2]Sr[sub 2]CaCu[sub 2]O[sub x] thick films by incorporating superconducting whiskers. Observation of the hysteresis behavior of critical current density in the film; Correlation between the current density and magnetic field; Efficacy of incorporating...

  • A broken-bond model for grain boundaries in face-centered cubic metals. Wolf, D. // Journal of Applied Physics;10/1/1990, Vol. 68 Issue 7, p3221 

    Presents a study which investigated the interrelation between the number of nearest-neighbor atomic bonds broken upon formation of a grain boundary in a face-centered cubic metals and the related zero-temperature boundary energy by atomistic simulation. Investigation of structure-property...

  • Topics in Lead-Free Solders: Restriction of Hazardous Substances Recast (RoHS2). Chada, Srinivas // JOM: The Journal of The Minerals, Metals & Materials Society (TM;Oct2013, Vol. 65 Issue 10, p1348 

    An introduction is presented in which the editor discusses various reports within the issue on topics including a predictive model for whisker formation based on local microstructure and grain boundary properties and the characterization of solder joint reliability using cyclic mechanical...

  • Simulated quenching to the zero-temperature limit of the grand-canonical ensemble. Phillpot, S. R.; Rickman, J. M. // Journal of Chemical Physics;8/15/1992, Vol. 97 Issue 4, p2651 

    A formalism for obtaining the zero-temperature structure of monocomponent solids in the grand-canonical ensemble is developed. The new methodology, grand-canonical simulated quenching, is validated by simulating systems initially containing a vacancy and an interstitial. As a first application,...

  • Acoustic Emission during Heating of Strained Aluminum. Plotnikov, V. A. // Technical Physics Letters;Aug2001, Vol. 27 Issue 8, p632 

    The phenomenon of acoustic emission during annealing of preliminarily strained polycrystalline aluminum was observed. Although processes accompanying the metal annealing belong to thermoactivated (microscopic motion, diffusion) phenomena, the acoustic oscillations are generated in the events of...

  • Study of the effect of grain boundary migration on hillock formation in Al thin films. Kim, Deok-kee; Nix, William D.; Vinci, Richard P.; Deal, Michael D.; Plummer, James D. // Journal of Applied Physics;7/15/2001, Vol. 90 Issue 2, p781 

    We have studied the effect of grain boundary migration on hillock formation in unpassivated Al thin films during thermal cycling. Hillocking occurs more frequently in Al films that experience grain growth during thermal cycling than in films with stabilized grain structures. The hillocking...

  • In situ electrical transport during isothermal annealing of nanocrystalline gold films. Ederth, J.; Kish, L. B.; Olsson, E.; Granqvist, C. G. // Journal of Applied Physics;2/1/2002, Vol. 91 Issue 3, p1529 

    Advanced gas deposition was used to produce nanocrystalline gold films under conditions giving four different deposition rates. Grain growth and structural modification of the grain boundaries were probed during annealing by use of in situ electrical transport measurements. Time dependent...

Share

Read the Article

Courtesy of VIRGINIA BEACH PUBLIC LIBRARY AND SYSTEM

Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics