On aluminum grain boundary structure and segregation
Publisher
The University of Arizona.Rights
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.Abstract
The effect of an alloying agent, such as Mg, on Al grain boundary microstructure and chemistry was investigated. HREM measurements on an Al-5% Mg Σ = 5 (310) grain boundary showed Al grain boundary structure modification because of the presence of Mg. Chemical analysis, through TEM/STEM EDS of Al-2% Mg alloy, indicated the possibility of Mg segregation at Al grain boundaries, although this should be further investigated. An experiment is proposed to determine the change in grain boundary torque with impurity chemical potential. Molecular dynamic simulations of the effect of segregated vacancies was also studied. This study showed that grain boundaries act as sinks for vacancies. In addition, the presence of vacancies caused a relocation of the grain boundary plane, through a sliding-migration, or atomic restructuring of the boundary depending upon the vacancy distribution.Type
textThesis-Reproduction (electronic)
Degree Name
M.S.Degree Level
mastersDegree Program
Graduate CollegeMaterials Science and Engineering