Abstract: The concept of computational materials design is deeply compelling --- specify the desired material properties, generate a set of candidate microstructures, evaluate the corresponding materials, and identify a few for experimental validation. Actually realizing this vision would require the ability to computationally generate realistic microstructures (among other things). I contend that we are not able to do so yet, whether by geometric models or physics-based simulations, and that our inability to do so imperils the grand vision.
Our group has been concerned with establishing the foundations of physics-based simulations of microstructure formation. Our particular emphasis has been on grain boundary motion, grain boundary faceting, and the topological transitions that occur to the grain boundary network. We have developed a volumetric finite element code with the intention of simulating grain growth in realistic materials (pending the availability of suitable grain boundary property data) and enabling direct comparison between simulations and three-dimensional microscopy data.
This code is not only a step toward practical computational materials design, but opens the door to other areas of inquiry. The idea to stabilize a microstructure by introducing low-energy annealing twins is part of the broader subject known as grain boundary engineering. We propose that, rather than increasing the fraction of low-energy boundaries, grain boundary engineering can most effectively stabilize a microstructure by increasing the fraction of faceted grain boundaries. This is discussed in the context of the two-dimensional Herring condition and the three-dimensional analogue.
Bio: Jeremy Mason's research interests focus on the use of theoretical and computational techniques to study the evolution of materials. This encompasses phenomena as diverse as the formation of solidification nuclei in a liquid, the appearance of low energy dislocation structures during the deformation of metals, and grain boundary motion during annealing and recrystallization. The study of these phenomena often requires that new simulation methods be developed to improve accuracy or reduce runtime, or that new mathematical methods be developed to analyze simulations results and make rigorous comparison with experiments. He pursues this with the intention of further developing the theoretical and computational side of "rational materials design".