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dc.contributor.authorHyde, Brianen_US
dc.date.accessioned2014-03-14T20:10:55Z
dc.date.available2014-03-14T20:10:55Z
dc.date.issued2004-04-20en_US
dc.identifier.otheretd-04262004-153825en_US
dc.identifier.urihttp://hdl.handle.net/10919/27315
dc.description.abstractAtomistic computer simulations were performed using embedded atom method interatomic potentials in α-Fe with impurities and defects. The effects of intergranular carbon on fracture toughness and the mechanisms of fracture were investigated. It was found that as the average grain size changes the dominant energy release mechanism also changes. Because of this the role of the intergranular carbon changes and these mechanisms compete affecting the fracture toughness differently with changing grain size. Grain boundary accommodation mechanisms are seen to be dominant in the fracture of nanocrystalline α-Fe. To supplement this work we investigate grain boundary sliding using the Σ = 5,(310)[001] symmetrical tilt grain boundary. We observe that in this special boundary sliding is governed by grain boundary dislocation activity with Burgers vectors belonging to the DSC lattice. The sliding process was found to occur through the nucleation and glide of partial grain boundary dislocations, with a secondary grain boundary structure playing an important role in the sliding process. Interstitial impurities and vacancies were introduced in the grain boundary to study their role as nucleation sites for the grain boundary dislocations. While vacancies and H interstitials act as preferred nucleation sites, C interstitials do not.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartdissertation.pdfen_US
dc.rightsI hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to Virginia Tech or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report.en_US
dc.subjectfractureen_US
dc.subjectMetalsen_US
dc.subjectgrain boundariesen_US
dc.subjectatomistic simulationsen_US
dc.subjectCen_US
dc.subjectFeen_US
dc.titleEffects of Carbon on Fracture Mechanisms in Nanocrystalline BCC Iron - Atomistic Simulationsen_US
dc.typeDissertationen_US
dc.contributor.departmentMaterials Science and Engineeringen_US
dc.description.degreePh. D.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineMaterials Science and Engineeringen_US
dc.contributor.committeechairFarkas, Dianaen_US
dc.contributor.committeememberCorcoran, Sean Geralden_US
dc.contributor.committeememberBatra, Romesh C.en_US
dc.contributor.committeememberReynolds, William T. Jr.en_US
dc.contributor.committeememberKampe, Stephen L.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-04262004-153825/en_US
dc.date.sdate2004-04-26en_US
dc.date.rdate2004-04-28
dc.date.adate2004-04-28en_US


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