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dc.contributor.authorLee, Soon Gien_US
dc.date.accessioned2006-09-01T19:32:35Z
dc.date.available2006-09-01T19:32:35Z
dc.date.issued2006-07-06en_US
dc.identifier.urihttp://hdl.handle.net/1853/11552
dc.description.abstractThe central goal of this research is to quantitatively characterize the relationships between processing, microstructure, and mechanical properties of important high-pressure die-cast (HPDC) Mg-alloys. For this purpose, a new digital image processing technique for automatic detection and segmentation of gas and shrinkage pores in the cast microstructure is developed and it is applied to quantitatively characterize the effects of HPDC process parameters on the size distribution and spatial arrangement of porosity. To get better insights into detailed geometry and distribution of porosity and other microstructural features, an efficient and unbiased montage based serial sectioning technique is applied for reconstruction of three-dimensional microstructures. The quantitative microstructural data have been correlated to the HPDC process parameters and the mechanical properties. The analysis has led to hypothesis of formation of new type of shrinkage porosity called, gas induced shrinkage porosity that has been substantiated via simple heat transfer simulations. The presence of inverse surface macrosegregation has been also shown for the first time in the HPDC Mg-alloys. An image analysis based technique has been proposed for simulations of realistic virtual microstructures that have realistic complex pore morphologies. These virtual microstructures can be implemented in the object oriented finite elements framework to model the variability in the fracture sensitive mechanical properties of the HPDC alloys.en_US
dc.format.extent12053856 bytes
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherGeorgia Institute of Technologyen_US
dc.subjectThree-dimensional microstructureen_US
dc.subjectCasting defects
dc.subjectPorosity
dc.subjectProcess conditions
dc.subjectPressure die-casting
dc.subjectMagnesium alloys
dc.titleQuantitative Characterization of Processing-Microstructure-Properties Relationships in Pressure Die-Cast Mg Alloysen_US
dc.typeDissertationen_US
dc.description.degreePh.D.en_US
dc.contributor.departmentMaterials Science and Engineeringen_US
dc.description.advisorCommittee Chair: Gokhale, Arun M.; Committee Member: Frost,James David; Committee Member: Liu, Meilin; Committee Member: McDowell, David M.; Committee Member: Thadhani, Naresh N.en_US


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