1-3. High-throughput materials computation and design: Key challenges for structural materials

Yunzhi Wang,
Department of Materials Science and Engineering, The Ohio State University

Abstract: Modern smart engineering structures demand location-specific component design where alloy composition and microstructure are optimized locally according to local service conditions. Such a location-specific design requires modeling capabilities incorporating specific transformation and deformation mechanisms operating in alloys having different compositions and microstructures under different service conditions. However, most modeling approaches to microstructure-property relationship today utilize highly simplistic descriptors of microstructures (such as average particle size and volume fraction) that are empirically correlated to the properties (e.g., cutting vs. looping). Such approaches are utterly inadequate for addressing the location-specific design needs. MGI/ICME will remain empirical data driven with limited predicting power and payoffs without the development of next generation modeling tools that incorporate specific transformation and deformation mechanisms operating in specific alloy systems under a given set of processing parameters, microstructure states and service conditions. Until then, high-throughput materials computation and design for critical structural applications will remain elusive.
         In this presentation, we focus on how to utilize multiscale modeling techniques to address this difficult challenge and develop mechanism-based and microstructure-sensitive modeling tools. In particular, using creep deformation in Ni-base superalloys as an example, we demonstrate how to integrate phase-field modeling with experimental characterization and use phase-field method to bridge ab initio calculations and crystal plasticity (CP) simulations to (a) identify transformation / deformation mechanisms and quantify their activation pathways, (b) provide “mechanism maps” andconstruct microstructure-sensitive constitutive laws for dislocation – microstructure interaction and co-evolution, and (c) develop an integrated phase-field + full-field FFT-based CP modeling framework for collective behavior of precipitate and dislocation microstructures during creep deformation.

        In the meantime, we will show how to use computational tools to explore non-conventional transformation/deformation pathways to engineer novel microstructures for unprecedented properties. In this regard, computation is not just simply following the experiments, helping to interpret experimentally observed phenomena, but leading the experiments in designing novel microstructures via exploring effectively the vast majority of alloy composition and processing spaces that cannot be accessed by the costly and time-consuming trial-and-error experimental approach.

       The work is supported by the US National Science Foundation.