Preliminary Exam Seminar: Courtney Clark
Event Date: | September 26, 2024 |
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Time: | 9am |
Location: | ARMS 2326 |
Priority: | No |
School or Program: | Materials Engineering |
College Calendar: | Show |
"Investigating Incipient Nucleation and Growth Dynamics of Electrodeposited Metal Matrix Composite Coatings"
Courtney Clark, MSE PhD Candidate
Advisor: Professor David Bahr
ABSTRACT
This presentation serves to evaluate electrolytic nucleation and growth (N&G) processes in the formation of uniform and composite coatings. Critical analysis and background on significant findings and knowledge gaps in the field will be provided through an examination of existing literature and avenues for future research will be proposed. Electrodeposition has been used for centuries to apply both functional and aesthetic coatings to a range of materials. This process is relatively simple, robust, and cost-effective for depositing films of one material onto another. There remain fundamental gaps in understanding of time-dependent microstructural control and key relationships between process parameters and coating performance. While it is generally understood how changing parameters (e.g. potential, electrolyte composition, temperature, pH, etc.) affect the resulting coating, the incipient processes that determine structures derived from N&G during electrodeposition have thus far only been probed using ex-situ, inferential, or averaged techniques. This work proposes a methodology for tailoring coating structure (size, shape, and texture) to exploit different physical properties (hardness, ductility, electrical conductivity, etc.) of electrodeposited coatings through processing variation and direct linkage to observable events and developing structure in real-time. Ultimately, incorporation of a second phase through co-deposition of particles added to the electrolyte solution will be evaluated. Entrapment of a second phase within a film brings with it additional challenges and variables, including electrolyte stabilization, mass transport of multiple species, and additional interface interactions.
Techniques including cyclic voltammetry and chronoamperometry will be used as a means of inferentially approximating relevant nucleation mechanisms and their ties to common models. Comparisons to conventional measurements by scanning electron microscopy with energy-dispersive x-ray spectroscopy will also be presented. An understanding of structure-property relationships of relevant materials, as well as processing-property relationships presented from empirical study will be critical for forming underlying hypothesis, and eventually a fundamental understanding of incipient processing-structure relationships for electrolytic N&G. Small angle x-ray scattering (SAXS) and x-ray
phase contrast imaging (XPCI) are invaluable tools for evaluating systems that require high spatial and temporal resolution. Developing a mechanism for applying SAXS and XPCI simultaneously, in conjunction with electrochemical testing, creates a unified system integrating direct observation, averaged measurements, and inferential analysis. This approach simultaneously probes system behavior across a broad range, thereby enhancing state of the art expectations for evaluation of high-resolution dynamic phenomena.
2024-09-26 09:00:00 2024-09-26 10:00:00 America/Indiana/Indianapolis Preliminary Exam Seminar: Courtney Clark ARMS 2326