Senior Scientist and Team Leader
Materials Science and Technology Division
Los Alamos National Laboratory
Seminar: Anticipating the Mechanical Performance of Metals Subjected to Extreme Environments
Abstract: Increasing societal needs for clean and safe energy pause formidable challenges to materials scientists. Indeed, the viability of most clean energy solutions being proposed (e.g., hydrogen-based energy production, storage, and transport; carbon capture; generation IV nuclear reactors) hinges upon our ability to understand and predict how metallic structural components behave over decades when subjected to extreme environments. In all structural and power generation applications, metals are simultaneously subjected to mechanical and thermal loads, and possibly irradiation. As the system is placed in service under those extreme environments, the destructive processes of materials aging (microstructure changes), creep/relaxation (internal stresses relaxation), and degradation (damage) are activated, ultimately leading to failure of the structure. Naturally, the time to failure depends on the underlying microstructure of the metal and on the constraints imposed.
This presentation will show how multi-scale modeling of the mechanical response and microstructure stability of metals (e.g., austenitic and ferritic type steels), in conjunction with multi-scale characterization can help establish direct, and statistically meaningful, linkages between the fingerprint of the microstructure of steels and their mechanical performance. Notably, focus will be placed on the counter-intuitive roles of solute and precipitates on the creep response of 347H (austenitic steel) and Gr91 (ferritic steel). Further, the presentation will illustrate how this understanding of the role of microstructure on the creep response of metals, combined with numerically efficient algorithms and simple data driven methods can be used to: (i) derive new material design guidelines and, (ii) anticipate how engineering scale structures will resist to extreme loading scenarios.
About the Speaker: Laurent Capolungo is a Scientist 5 and team leader at Los Alamos National Laboratory. Prior to this he was an associate Professor 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 codeveloped LAROMance; a suite of data driven constitutive finite element level models sensitive to the underlying microstructure of metals. Dr. Capolungo is the co-author of more than 150 journal articles that have been cited more than 5300 hundred times (h-index 41). 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.