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dc.contributor.advisorKacher, Joshua
dc.contributor.authorYoo, Yung Suk
dc.date.accessioned2021-06-10T13:53:00Z
dc.date.available2021-06-10T13:53:00Z
dc.date.created2020-05
dc.date.issued2020-03-31
dc.date.submittedMay 2020
dc.identifier.urihttp://hdl.handle.net/1853/64586
dc.description.abstractAluminum alloys have been enjoying the spotlight in recent years as the next generation alloy for a wide variety of applications. Their potentially waste-free recyclability, excellent corrosion resistance, and desirable balance in physical properties—low density and high strength-to-weight ratio—makes them an ideal candidate material for efficient and environmentally-friendly products. Mechanical properties of aluminum alloys can be engineered to suit the requirements for different functions by controlling the microstructural features. Naturally, the variety of alloying elements, microstructural features, and thermomechanical processes produce complex microstructures that deform heterogeneously under different mechanical loading conditions. To get a better understanding of the failure mechanism of aluminum alloys, this dissertation will explore the effects of dispersoids, a type of second phase particle, on the crack initiation and propagation behaviors. A multiscale electron microscopy-approach was employed to characterize different aspects of the microstructure and their localized deformation behavior. This work is divided into two parts. The first part will delve into the crack initiation mechanism of AA6451 during three-point bending and the influence of microstructural features on each step of the process. It will also discuss the effects of variation in alloying elements and tempering conditions on the microstructure evolution and localized deformation behavior of AA6451. The second part involves studying the crack propagation behavior of deep drawn and necked AA3xxx. The dispersoid effects on crack growth direction will be discussed in depth. These findings will ultimately help scientists gain a better mechanistic understanding of defect interactions during extreme stress.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherGeorgia Institute of Technology
dc.subjectMicrostructure
dc.subjectTransmission electron microscopy
dc.subjectelectron backscatter diffraction, Transmission Kikuchi diffraction
dc.subjectaluminum, three-point bending
dc.subjectdeep drawing
dc.titleEffects of Microstructure on Crack Initiation in AA6451 and Crack Propagation in AA3xxx
dc.typeDissertation
dc.description.degreePh.D.
dc.contributor.departmentMaterials Science and Engineering
thesis.degree.levelDoctoral
dc.contributor.committeeMemberMuhlstein, Christopher
dc.contributor.committeeMemberPierron, Olivier
dc.contributor.committeeMemberNeu, Richard
dc.contributor.committeeMemberDas, Sazol
dc.date.updated2021-06-10T13:53:00Z


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