Effects of strain variations on aging response and corrosion properties of third generation Al-Li alloys
dc.contributor.advisor | Kaufman, Michael J. | |
dc.contributor.author | Wright, Ellen E. | |
dc.date.accessioned | 2016-10-04T15:59:11Z | |
dc.date.accessioned | 2022-02-03T12:56:17Z | |
dc.date.available | 2016-10-04T15:59:11Z | |
dc.date.available | 2022-02-03T12:56:17Z | |
dc.date.issued | 2016 | |
dc.identifier | T 8151 | |
dc.identifier.uri | https://hdl.handle.net/11124/170450 | |
dc.description | Includes bibliographical references. | |
dc.description | 2016 Fall. | |
dc.description.abstract | Due to their high specific strength (strength/density) and specific stiffness (elastic modulus/density), Al-Li alloys are attractive alloys for structural aircraft applications. To produce contoured aircraft components from Al-Li wrought products, stretch forming prior to aging is a common manufacturing technique. The effects of different amounts of tensile straining (0-9%) on the mechanical, microstructural, and corrosion properties of two third generation Al-Li alloys (2099 and 2196) were investigated. In addition to typical characterization techniques, electron backscatter diffraction (EBSD), 2D micro-digital image correlation (DIC), and scanning Kelvin probe force microscopy (SKPFM) were used to examine site-specific effects of orientation, micro-strain evolution during straining, and surface potential on corrosion, respectively. Tapping mode atomic force microscopy (AFM) was also performed to study galvanic corrosion in artificial seawater (3.5% NaCl) as it occurred in-situ. There was evidence of intergranular corrosion for 0% strain conditions, but the dominant form of corrosion was localized pitting for all specimens except Alloy 2196 strained 0%. Pitting initiated at grain boundaries and triple points. In many cases, pitting extended into particular grains and was elongated in the extrusion direction. Regions of high micro-strain preferentially corroded, and large, recrystallized grains in mostly unrecrystallized microstructures were detrimental to corrosion properties. Recommendations for improved thermomechanical processing and/or alloying to promote corrosion resistance of 2XXX series Al-Li alloys were investigated. | |
dc.format.medium | born digital | |
dc.format.medium | doctoral dissertations | |
dc.language | English | |
dc.language.iso | eng | |
dc.publisher | Colorado School of Mines. Arthur Lakes Library | |
dc.relation.ispartof | 2016 - Mines Theses & Dissertations | |
dc.rights | Copyright of the original work is retained by the author. | |
dc.subject | atomic force microscopy | |
dc.subject | digital image correlation | |
dc.subject | stretch forming | |
dc.subject | corrosion | |
dc.subject | aluminum-lithium | |
dc.subject | strain | |
dc.title | Effects of strain variations on aging response and corrosion properties of third generation Al-Li alloys | |
dc.type | Text | |
dc.contributor.committeemember | Field, Robert | |
dc.contributor.committeemember | Findley, Kip Owen | |
dc.contributor.committeemember | Bourne, Gerald | |
dc.contributor.committeemember | Berger, John R. | |
dc.contributor.committeemember | Weber, Gary Robert | |
thesis.degree.name | Doctor of Philosophy (Ph.D.) | |
thesis.degree.level | Doctoral | |
thesis.degree.discipline | Metallurgical and Materials Engineering | |
thesis.degree.grantor | Colorado School of Mines |