MAE Seminar: Katerina E. Aifantis, Introducing New Interface Energy Terms for Capturing Materials Behavior at the Nanoscale

Date/Time

08/30/2018
4:00 pm-5:00 pm
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Location

303 MAE-A
939 Sweetwater Drive
Gainesville, FL 32611

Details

Tenure & Promotion Candidate

Introducing New Interface Energy Terms for Capturing Materials Behavior at the Nanoscale

Katerina E. Aifantis
Mechanical and Aerospace Engineering
University of Florida

Abstract
The optoelectronic and mechanical properties at the nanoscale can differ drastically than those at the microscale. This is attributed to the large surface to volume ratio that characterizes nanomaterials. In the present talk it will be illustrated that introducing new interface energy terms, in the materials constitutive equations, can allow the interpretation of the experimental stress-strain response observed for nanopillars, micropillars and nanocrystals, which classical mechanics cannot capture. The materials systems to be examined are bi and tri-crystalline Fe-Si alloys, in which nanoindentation is performed near the vicinity of the grain boundary. Furthermore, the behaviour of nanopolycrystalline materials, such as Cu, W, Ni, which exhibit the inverse Hall-Petch transition can also be captured through consideration of such new interface energy terms. A vital application of this framework is to understand the mechanical behavior of Li-ion batteries, as the limiting factor in commercializing next-generation Si anodes, is the fracture they experience during electrochemical cycling. Case studies therefore, for developing design criteria for such nanocomposite anodes will be presented.

Biography
Katerina E. Aifantis began her research with US National Science Foundation Graduate Research Fellowship, and obtained her Master’s from the University of Cambridge and her PhD from the University of Groningen at the age of 21, becoming the youngest PhD holder in the history of The Netherlands. In 2008, she became the youngest recipient (at 24) of the European Research Council Grant to set up her on lab at the Aristotle University of Thessaloniki for studying nanomaterials and their applications in energy and biology. In 2013 she joined the University of Arizona as an associate professor and in 2017 she moved to the department of Mechanical and Aerospace Engineering of the University of Florida. Through funding from the Basic Energy Sciences Office of the Department of Energy she tries to understand the effect of interfaces in materials behavior, while the National Science Foundation is funding her work on anodes for Li-in and Na-ion batteries.

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