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dc.creatorCarpenter, Alexander James
dc.date.accessioned2011-06-17T16:37:04Z
dc.date.accessioned2011-06-17T16:37:20Z
dc.date.available2011-06-17T16:37:04Z
dc.date.available2011-06-17T16:37:20Z
dc.date.created2011-05
dc.date.issued2011-06-17
dc.date.submittedMay 2011
dc.identifier.urihttp://hdl.handle.net/2152/ETD-UT-2011-05-2681
dc.descriptiontext
dc.description.abstractStatic abnormal grain growth (SAGG) was studied in Al-Mg alloy AA5182 sheet by varying four processing parameters: deformation temperature, strain rate, annealing temperature, and annealing time. SAGG is a secondary recrystallization process related to geometric dynamic recrystallization (GDRX) and requires both deformation at elevated temperature and subsequent static annealing. A minimum temperature is required for both SAGG and GDRX. Recrystallized grains only develop at strains larger than the critical strain for SAGG, [epsilon]SAGG. The size of the recrystallized grains is inversely related to and controlled by the density of SAGG nuclei, which increases as local strain increases. The results of this study suggest that SAGG is controlled by two thermally-activated mechanisms, dynamic recovery and recrystallization. During deformation, dynamic recovery increases as deformation temperature increases or strain rate decreases, increasing the critical strain for SAGG. SAGG is subject to an incubation time that decreases as annealing temperature increases. SAGG can produce grains large enough to reduce yield strength by 20 to 50 percent. The results of this study suggest strategies for avoiding SAGG during hot-metal forming operations by varying processing conditions to increase [epsilon]SAGG.
dc.format.mimetypeapplication/pdf
dc.language.isoeng
dc.subjectSAGG
dc.subjectStatic abnormal grain growth
dc.subjectAA5182
dc.subjectDeformation temperature
dc.subjectStrain rate
dc.subjectAnnealing
dc.subjectRecrystallization
dc.titleThe effects of processing conditions on static abnormal grain growth in Al-Mg alloy AA5182
dc.date.updated2011-06-17T16:37:20Z
dc.description.departmentMechanical Engineering
dc.type.genrethesis*
thesis.degree.departmentMechanical Engineering
thesis.degree.disciplineMechanical Engineering
thesis.degree.grantorUniversity of Texas at Austin
thesis.degree.levelMasters
thesis.degree.nameMaster of Science in Engineering


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