Mechanical Engineering is excited to announce the creation of a UofU-BYU Seminar Exchange. Our first seminar is planned for

Thursday, December 3, 2015
11:00 am – 12:00 noon
in the Milner Executive Board Room
(0560 MEK)

“Modeling Grain Boundaries in Crystalline Metals and Deformation in Amorphous Metals”

Eric R Homer, Ph.D.
Assistant Professor in the Department of Mechanical Engineering at the Brigham Young University of Provo, Utah

Abstract: Grain boundaries in polycrystalline materials play an important role in strength, ductility, conductivity, and creep and corrosions resistance. However, the state space of possible grain boundaries is vast and largely unexplored. Atomistic surveys of large numbers of grain boundaries and their properties, including energy, excess volume, mobility, and shear coupling, have discovered interesting trends and phenomena. Among these interesting phenomena is possible non-thermally activated grain boundary motion, mobilities that are constant or increase with decreasing temperature. Additionally, recent publication of symmetries in grain boundary plane orientations has enabled more effective descriptions of grain boundary crystallography. Using this new representation, structure-property relationships, such as energy, naturally emerge and indicate that the vast grain boundary space may be more tractable than expected.

In contrast, amorphous metals, without any crystalline structure or grain boundaries, have impressive mechanical properties that exceed their crystalline counterparts in many cases. However, they have a major flaw, these metals shatter like a glass upon failure. Mesoscale modeling provides a unique opportunity to investigate the failure mechanisms, shear bands, that propagate on millisecond time scales. The modeling approach also enables the examination of mechanisms to increase toughness, such as the addition of crystalline inclusions in amorphous metal composites.

Bio: Eric R. Homer is an assistant professor in the Department of Mechanical Engineering at Brigham Young University. He received B.S. and M.S. degrees in Mechanical Engineering from Brigham Young University in 2006 and a Ph.D. in Materials Science & Engineering from Massachusetts Institute of Technology in 2010. Prof. Homer then spent one year as a postdoctoral appointee in the Computational Materials Science & Engineering at Sandia National Laboratories, Albuquerque, NM. His areas of research include grain boundary structure-property relationships, mechanical behavior of amorphous metals, microstructure characterization, atomistic simulations, and microstructural modeling.