Modeling the deformation and failure behavior of FCC and HCP nanocrystalline materials

As foreseen by Richard Feynman in his famous talk titled There's Plenty of Room at the Bottom in 1959, scientists nowadays are miniaturizing structures in materials to achieve better performance as concerned in technical applications. Reducing grain sizes in polycrystalline materials into the range of less than 100nm, for example, could achieve extraordinary high strength in these so called nanocrystalline (nc) materials. The reduced grain size gives rise to new deformation mechanisms in nc materials. It is now widely accepted that there is a strong interplay between dislocation-based deformation in the crystalline grain interiors and the inelastic deformation mechanisms operative in the grain-boundary regions. Grain-boundary regions play an increasingly significant role as the grain size decreases below the 100nm level. In this dissertation, constitutive models have been developed to investigate the deformation mechanisms of nc materials, with focus on modeling grain-boundary decohesion in nc materials. Two micromechanical models have been developed to capture the deformation in grain boundaries in nc materials.

Department dc:contributor.department

Massachusetts Institute of Technology. Department of Mechanical Engineering

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2006

Author dc:creator

• Wei, Yujie, Ph. D. Massachusetts Institute of Technology

Advisor dc:contributor.advisor

• Lallit Anand.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/35626

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/35626