| Type of Document |
Master's Thesis |
| Author |
Latapie, Antoine Nicolas
|
| Author's Email Address |
alatapie@vt.edu |
| URN |
etd-05242002-141644 |
| Title |
Molecular Dynamics Investigation on the Fracture Behavior of Nanocrystalline Fe |
| Degree |
Master of Science |
| Department |
Materials Science and Engineering |
| Advisory Committee |
| Advisor Name |
Title |
| Farkas, Diana |
Committee Chair |
| Corcoran, Sean Gerald |
Committee Member |
| Reynolds, William T. Jr. |
Committee Member |
|
| Keywords |
- molecular statics
- computer simulation
- fracture toughness
- iron
- Fe
- fracture
- alpha iron.
- nanocrystalline
- crack propagation
- molecular dynamics
|
| Date of Defense |
2002-05-20 |
| Availability |
unrestricted |
Abstract
Crack propagation studies in nanocrystalline alpha-iron samples with grain sizes ranging from 6 to 12 nm are reported at temperatures ranging from 100K to 600K using atomistic simulations. For all grain sizes, a combination of intragranular and intergranular fracture is observed. Mechanisms such as grain boundary accommodation, grain boundary triple junction, grain nucleation and grain rotation are observed to dictate the plastic deformation energy release. Intergranular fracture is shown to proceed by the coalescence of nanovoids formed at the grain boundaries ahead of the crack. The simulations also show that at an atomistic scale the fracture resistance and plastic deformation energy release mechanisms increase with increasing temperature. Finally a softening of the material occurs with decreasing grain size. The elastic properties are found to decrease and the fracture resistance to increase with decreasing grain size.
|
| Files |
| Filename |
Size |
Approximate Download Time
(Hours:Minutes:Seconds)
|
| 28.8 Modem |
56K Modem |
ISDN (64 Kb) |
ISDN (128 Kb) |
Higher-speed Access |
| |
Thesis_Latapie.pdf |
4.82 Mb |
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00:11:29 |
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