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Description
Title: | Dislocation -Obstacle Interactions in Aluminum Alloys |
Author(s): | Clark, Blythe Gore |
Doctoral Committee Chair(s): | Robertson, Ian M. |
Department / Program: | Materials Science and Engineering |
Discipline: | Materials Science and Engineering |
Degree Granting Institution: | University of Illinois at Urbana-Champaign |
Degree: | Ph.D. |
Genre: | Dissertation |
Subject(s): | Engineering, Materials Science |
Abstract: | This thesis examines two types of dislocation-obstacle interactions: dislocation-particle interactions during creep deformation, and dislocation-loop interactions during deformation at room temperature. Dislocation-particle interaction studies in Al-Zn-Mg-Cu-Zr, Al-4Mg-0.3Sc, and Al-0.3Sc showed that temperature, coherency, and particle size play a role in determining the dominant bypass mechanism, and that interactions are more complex than what is considered in current models. A new mechanism for elevated temperature bypass of particles during creep deformation was revealed, in which dislocations interact directly with the particle-matrix interface, altering the interfacial structure, and affecting subsequent dislocation interactions. These results are discussed in relation to macroscopic behavior in steady-state creep experiments. In addition, dislocation-loop interaction studies show interactions to be of two types: intersection and elastic interactions. In-situ observations show annihilation, rotation, and repulsion of loops due to dislocation interactions. Comparison with current molecular dynamics simulations highlights the need to better understand these interactions in order to improve models for irradiated materials. |
Issue Date: | 2006 |
Type: | Text |
Language: | English |
Description: | 126 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2006. |
URI: | http://hdl.handle.net/2142/82786 |
Other Identifier(s): | (MiAaPQ)AAI3242826 |
Date Available in IDEALS: | 2015-09-25 |
Date Deposited: | 2006 |
This item appears in the following Collection(s)
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Dissertations and Theses - Materials Science and Engineering
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Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois