- This event has passed.
MAE Seminar Series: Laurent Capolungo
November 3, 2023 @ 10:00 am - 11:00 am
Title:
Twinning in metals with hexagonal close packed crystal symmetry: on the origins of network formation.
Abstract:
Twinning and martensitic transformations accommodate strain during plastic deformation of materials with hexagonal close packed crystal symmetry via the formation and growth of reoriented/transformed 3D domains. The kinetics of propagation of these domains is controlled by the intrinsic mobility of the facets/interfacial defects separating them from the host phase, by the internal stresses acting as driving forces for transformations to occur, and by the presence of local defects which can either impede or favor the propagation process. Naturally, transmission of twins across grain boundaries is suspected to play an important role in forming complex twin networks.
The material’s science community, surprisingly, has focused on twin and martensitic domain morphology and interface mobility mostly from a 2D perspective. This presentation will address the full 3D character of transformed domains and of their associated networks. Leveraging atomic and micron-scales characterization techniques in combination with both simulation and analysis tools, the aims are to unravel the nature of interfacial defects that mediate twinning and correlate their intrinsic properties (mobilities, metastable states) to the kinetics of microstructure evolutions. Among others, this presentation will discuss how twin networks form within complex microstructure via the activation of transmission events across grain boundaries. Critically, the work to be presented will demonstrate how twin transmission across grain boundaries differs from slip transmission; thereby leading to particularly complex and convoluted 3D networks of twins.
Bio:
Laurent Capolungo is a Scientist 5 and team leader at Los Alamos National Laboratory (LANL). Prior to this, he was an associate Professor (tenured) at the Georgia Institute of Technology where he obtained his PhD in 2007.
Dr. Capolungo has 20 years of experience in computational mechanics. Laurent is an expert in multiscale modeling of metals subjected to extreme environments. He and his colleagues have developed several advanced numerical tools allowing for: (i) automated microstructure data analysis, (ii) simulations of the collective behavior of dislocations (discrete dislocation dynamics), (iii) simulations of the mechanical response of polycrystal using mean-field and full-field methods and, (iv) simulation of radiation induced damage in polycrystals. In recent years, Laurent co-developed LAROMance; a suite of data driven constitutive finite element level models sensitive to the underlying microstructure of metals which was a R&D100 award finalist in 2022.
Dr. Capolungo is the co-author of more than 150 journal articles that have been cited more than 5600 hundred times (h-index 42). Dr. Capolungo officiates as a referee for more than 10 international journals including JMPS, Acta Mater Scripta Mater (for which he received an outstanding performance award in 2016). He is also a member of the editorial board of the international journal of plasticity.
Over his career Dr capolungo has co-lead more than 10 research projects support by the European commission, NSF, DoE NE, DoE FECM, DoE BES etc.. Currently, Dr Capolungo is the PI or co-PI of several large-scale programs. Among others Dr Capolungo is national deputy director of consortium ExtremeMAT and the PI of a recently awarded project supported by SciDAC on the topic metals subjected to molten salt reactor environments.
