Molecular Dynamics Investigation on the Fracture Behavior of Nanocrystalline Fe

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.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

masters

Discipline thesis:degree_discipline

Materials Science and Engineering

Department dc:contributor.department

Materials Science and Engineering

Grantor dc:publisher

Virginia Tech

Year dc:date.issued

2002

Author dc:creator

• Latapie, Antoine Nicolas

Chair dc:contributor.committeechair

• Farkas, Diana

Committee members dc:contributor.committeemember

• Corcoran, Sean G.
• Reynolds, William T. Jr.

• molecular statics
• computer simulation
• fracture toughness
• iron
• Fe
• fracture
• alpha iron.
• nanocrystalline
• crack propagation
• molecular dynamics

Statement dc:rights

• In Copyright

Licence dc:rights.uri

• http://rightsstatements.org/vocab/InC/1.0/

Dc Identifier Other

etd-05242002-141644

OAI identifier oai:identifier

oai:vtechworks.lib.vt.edu:10919/33176