Title page for ETD etd-06242006-163956


Type of Document Dissertation
Author Crowson, Douglas A.
Author's Email Address dcrowson@vt.edu
URN etd-06242006-163956
Title Stability of Nanoporous Metals
Degree PhD
Department Materials Science and Engineering
Advisory Committee
Advisor Name Title
Corcoran, Sean Gerald Committee Chair
Farkas, Diana Committee Co-Chair
Batra, Romesh C. Committee Member
Reynolds, William T. Jr. Committee Member
Wang, Yu Committee Member
Keywords
  • surface relaxation
  • EAM
  • dealloying
  • porous metals
  • surface stress
Date of Defense 2006-06-14
Availability unrestricted
Abstract
A study of the stability of bicontinuous nanoporous metals is presented. Atomic scale simulations are used to probe the dominant mechanisms of geometric relaxation in these materials. A method is presented for generating model bicontinuous metal / void structures for use in atomistic simulations of bicontinuous nanoporous solids. The structures are generated with periodic boundary conditions using a phase-field model to simulate the spinodal decomposition of an ideal system. One phase in the model is then associated with the pore volume while the other phase is associated with the metal ligaments. Small angle neutron scattering was used to quantitatively compare experimental samples to those generated by the phase field method.

EAM results using model structures with experimentally accessible length scales are presented which demonstrate the potential of such simulations in understanding the behavior of nanoporous metals. Simulated relaxations of these structures, as well as the relaxation of model spherical clusters, indicate that the surface relaxation effect dominates the overall dimensional relaxation of np-metals post processing. Capillary effects play a secondary role in the overall relaxation. The simulation results presented also identify a maximum surface area to volume ratio necessary to maintain mechanical stability beyond which the pore structure collapses.

Files
  Filename       Size       Approximate Download Time (Hours:Minutes:Seconds) 
 
 28.8 Modem   56K Modem   ISDN (64 Kb)   ISDN (128 Kb)   Higher-speed Access 
  Crowson_3803.pdf 97.73 Kb 00:00:27 00:00:13 00:00:12 00:00:06 < 00:00:01
  Crowson_3803online.pdf 91.41 Kb 00:00:25 00:00:13 00:00:11 00:00:05 < 00:00:01
  DA_Crowson_Stability_of_Nanoporous_Metals.pdf 2.10 Mb 00:09:43 00:04:59 00:04:22 00:02:11 00:00:11
  permission_elsevier.pdf 88.14 Kb 00:00:24 00:00:12 00:00:11 00:00:05 < 00:00:01

Browse All Available ETDs by ( Author | Department )

dla home
etds imagebase journals news ereserve special collections
virgnia tech home contact dla university libraries

If you have questions or technical problems, please Contact DLA.