CAREER: Understanding Interface-Mediated Deformation in Layered Composites through Modeling and Experiment

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Metallic nanolayered composites are a special class of metallic composite materials with ultra-fine layer thicknesses which impart unique behavior. They exhibit large increases in strength compared to larger-scale bulk constituents. In some cases, they display increased ductility, high radiation damage tolerance, shock resistance, and thermal stability; thus showing great potential for applications in a variety of fields. These materials can lead to new performance levels and energy efficiency not achievable with current materials and thus can have a significant economic impact. However, a lack of understanding of the underlying mechanisms that control the properties of metallic nano layered composites severely limits our current ability to process and tailor them. This Faculty Early Career Development (CAREER) award supports fundamental research to advance fundamental knowledge, develop computational tools and provide design guidelines for metallic nanolayered composites with exceptional controllable properties. Results from this research have the potential to enhance U.S. competitiveness within the markets of aerospace and electronic devices. As part of this project, the research results will be made available to other researchers and the general public through publications and active participation in conferences and workshops. With the aim of educating the twenty-first century workforce, this work also increases the exposure of high school students to science and technology concepts through outreach programs, and provides invaluable educational opportunities for student researchers to collaborate with National Laboratories.This research is to develop a new experimentally-validated multiscale-modeling approach to elucidate the mechanical properties and deformation mechanisms of metallic nanolayered composites. The specific research objectives are: (i) to explore the influence of dislocation-interface interactions on the strength of metallic nanolayered composites; (ii) to investigate the effects of the interface structure and layer thickness on the ductility and plastic instability; (iii) to identify the roles of interface structure and material properties of constituents in the texture evolution during the accumulative roll bonding process; (iv) to reveal the microscopic mechanisms for cyclic deformation behavior of metallic nanolayered composites. The research results will provide insights into the interaction between dislocations and interfaces and their interplay with macroscopically applied fields. The seamless integration of the multiscale-modeling approach and experiment studies will allow one-to-one comparisons between fundamental defect models and deformation experiments on nanostructured materials, creating a unique opportunity for testing the applicability of state-of-the-art theories of crystal defects in real materials systems.