The processing of a structural material controls the development of its microstructure, and the formation of defects that ultimately dictate its properties and performance. In technological materials such as metallic alloys, microstructures typically emerge during the initial stage of solidification from the liquid phase. As such, understanding the development of microstructural features that originate during solidification, such as grain textures or dendritic patterns, are key to the development of new materials and processes with microstructures designed to yield outstanding properties and performance in use.

From a fundamental standpoint, complex solidification microstructures, such as dendrites, arise from a subtle interplay between phenomena across a broad range of scales: from atom attachment kinetics at the solid-liquid interface to macroscopic bulk transport of heat and species in the different phases. As such, solidification modeling holds major scale-bridging challenges, and the fundamental understanding of solidification still holds long-standing unknowns, such as the mechanisms of intra- and inter-grain dendritic microstructure selection, or the origin of morphological transitions in metallic microstructures.

This talk will focus on theory, modeling, and simulation of crystal growth at scales ranging from a single dendrite (~ micrometer) to a grain structure (~ centimeter), combining atomistic, phase-field, and multiscale techniques. I will highlight how simulations may be used to reveal salient mechanisms of microstructure selection, e.g. the selection of grain boundaries and microstructural length scales, such as dendritic spacings. Simulations are motivated, illustrated, and validated by joint experiments. Remaining outstanding challenges and missing links will be highlighted, as well as strategies and ongoing efforts to address them.

Biography

Damien Tourret(damien.tourret@imdea.org) is a staff researcher at IMDEA Materials Institute in Madrid (Spain), a Marie Sklodowska-Curie fellow, and the leader of the research group on Modeling and Simulation of Materials Processing.

Damien Tourret received a MSc in Mechanical Engineering from INSA Toulouse (France) in 2006 and a PhD in Materials Science & Engineering from Ecole des Mines de Paris (France) in 2009. Before joining IMDEA Materials in 2017, Damien was a Director's Postdoctoral Fellow at Los Alamos National Laboratory (Los Alamos, NM, USA) from 2014 to 2017. He also held postdoctoral positions at the German Aerospace Center (DLR, Cologne, Germany) from 2010 to 2011, and at Northeastern University (Boston, MA, USA) from 2011 to 2014.

His main research interests revolve around linking materials processing routes to microstructures and properties, with a particular emphasis on multi-scale modeling of solidification and phase transformations in metallurgical processing of metals and alloys.