AEM Seminar:
Mesoscale Investigation of Dislocation-Grain Boundary Interactions in Metals and Alloys
Abstract:
"Microstructure” refers to the large number of crystal grains and their
corresponding boundaries that make up metals and alloys. A material’s
ability to accommodate stress induced through mechanical loads is
dependent on the ease with which dislocations can
move through the microstructure to relieve accumulated stress. Grain
boundaries (GBs) are the largest impediment to this motion – this is
true to some extent regardless of the grain size. The GB structure
defines whether a dislocation can transmit across a
GB, be partially absorbed at the GB, or glide along the GB and re-emit,
altering the GB structure. For poor alignment between grains,
dislocations can pile-up against GBs, building localized internal stress
regions that work harden the material. This preferential
localization of strains and plastic deformation at specific
microstructural sites are precursors to damage nucleation. Thus,
understanding and predicting dislocation-grain boundary interactions are
key for capturing mechanical response, but they are also incredibly
complex in part due to the vast number of possible grain boundaries and
corresponding dislocation interactions. This talk will focus on recent
multiscale modeling efforts addressing dislocation-grain boundary
interactions, with particular focus on methods/approaches
that can be used to scale information.
Bio:
Dr. Abigail Hunter earned a Ph.D. in Mechanical Engineering from Purdue
University in 2011, and a B.S. degree in Mechanical Engineering from the
University of Utah in 2006. Following her Ph.D., she joined Los Alamon
National Laboratory (LANL) as a postdoctoral
research associate in 2011 in the X Computational Physics (XCP)
Division, and then converted to a staff scientist in 2012. She is
currently the group leader for the Materials and Physical Data Group
within XCP and the Deputy Director for the Institute of Materials
Science at LANL. She is also the Editor-in-Chief for the ASME Journal
of Engineering Materials and Technology, and an Associate Editor for the
International Journal of Plasticity. In 2020, she received the Alum of
the Year Award from the Department of Mechanical
Engineering at the University of Utah in recognition for outstanding
achievements in Mechanical Engineering and service to the community. In
2019 she was nationally recognized as a recipient of the Presidential
Early Career Award for Scientists and Engineers
(PECASE) for work developing and implementing models addressing brittle
damage and dislocation dynamics in metals, which are two capabilities
designed to address questions concerning advanced manufacturing of new
materials. Her research interests include modeling
the strength and damage of metals and alloys at both the meso- and
macro-scales, with specific interest in connections between
microstructure, dislocation-based deformation behaviors, and overall
material response.
*Refreshments to follow in 209 Akerman Hall