dc.contributor.advisor | Zhang, Xinghang | |
dc.creator | Liu, Yue | |
dc.date.accessioned | 2015-01-09T20:26:32Z | |
dc.date.available | 2016-05-01T05:30:49Z | |
dc.date.created | 2014-05 | |
dc.date.issued | 2014-04-28 | |
dc.date.submitted | May 2014 | |
dc.identifier.uri | https://hdl.handle.net/1969.1/152621 | |
dc.description.abstract | Low energy planar defects such as twin boundaries have been employed to
strengthen materials effectively with insignificant loss of the conductivity and ductility.
High density growth twins can be formed in low stacking fault energy (SFE) metals, such
as copper (Cu) and silver (Ag). However, low SFE metal cobalt (Co) received little
attention due to the complex coexistence of hexagonal close-packed (HCP) and face-centered
cubic (FCC) structure. The focus of this research is to identify the strengthening
mechanisms of planar defects such as twin boundaries, stacking faults, and layer
interfaces in epitaxial FCC/HCP Co, and Cu/Co multilayers. Our studies show that
epitaxial Cu/Co multilayers with different texture have drastic different mechanical
properties, dictated by the transmission of partial vs. full dislocations across layer
interfaces. Furthermore the mechanical properties of epitaxial Co are dominated by high
density stacking faults. Moreover, by applying advanced nanoindentation techniques,
such as thermal-drift corrected strain-rate sensitivity measurement, the mechanical
properties including strain-rate sensitivity is accurately determined. By using in situ
nanoindentation under transmission electron microscope (TEM), we determined
deformation physics of nanotwinned Cu, including detwinning, dislocation-twin
interactions and work hardening. This project provides an important new perspective to
investigate mechanical behavior of nanostructured metals with high density stacking
faults. | en |
dc.format.mimetype | application/pdf | |
dc.language.iso | en | |
dc.subject | nanoindentation | en |
dc.subject | Transmission electron microscopy | en |
dc.subject | Magnetron sputtering | en |
dc.subject | Thin film | en |
dc.subject | X-ray diffraction | en |
dc.title | Strengthening Mechanisms of Sputtered Copper, Cobalt and Their Nanocomposites | en |
dc.type | Thesis | en |
thesis.degree.department | Materials Science and Engineering | en |
thesis.degree.discipline | Materials Science and Engineering | en |
thesis.degree.grantor | Texas A & M University | en |
thesis.degree.name | Doctor of Philosophy | en |
thesis.degree.level | Doctoral | en |
dc.contributor.committeeMember | Hartwig, Karl T | |
dc.contributor.committeeMember | Karaman, Ibrahim | |
dc.contributor.committeeMember | Wang, Haiyan | |
dc.type.material | text | en |
dc.date.updated | 2015-01-09T20:26:32Z | |
local.embargo.terms | 2016-05-01 | |
local.etdauthor.orcid | 0000-0001-8518-5734 | |