CAREER: Nanocrystalline Grain Boundary Network Engineering Enabled by New Deformation Mechanisms

University Of California-Irvine, Irvine CA

Investigators

Abstract

TECHNICAL SUMMARY: This CAREER award supports a research project to reveal how nanocrystalline grain boundary networks evolve during plastic deformation and understand how this evolution affects subsequent mechanical response. It is hypothesized that the unique deformation physics of nanocrystalline metals will allow for manipulation of the grain boundary network through thermomechanical treatments, connecting the heretofore separate fields of grain boundary engineering and nanostructured materials. Specifically, the research is driven by three technical objectives: (1) characterize the details of the grain boundary network in nanocrystalline materials, (2) measure the evolution of grain boundary character distribution and network topology under thermomechanical cycling, and (3) leverage the insight gained to develop new materials theory which connects grain boundary network details to mechanical behavior. This work will combine advanced characterization techniques, carefully designed mechanical testing, and atomistic simulations to meet these objectives. The insights obtained here will be used to connect interfacial network character to nanocrystalline mechanical behavior and to optimize the design of interfaces in nanostructured materials. NON-TECHNICAL SUMMARY: This program is motivated by several technologically relevant questions: (1) How are the properties of nanostructured materials influenced by the details of their grain boundary networks? (2) How does mechanical deformation, both at room and elevated temperatures, alter these interfacial networks? (3) Can the grain boundary network be optimized, through thermomechanical treatments, to engineer better nanomaterials? This work will provide a roadmap for controlling the details of grain boundary structure and the interconnecting network formed by all boundaries in order to create improved nanostructured materials and enable next-generation technologies. In addition, this project supports an outreach program to broaden the participation of underrepresented minorities and women in Science, Technology, Engineering, and Mathematics (STEM) fields. A multi-tiered approach will be implemented to engage and empower high school students and teachers, as well as undergraduate university students, through direct laboratory experiences and exposure to interdisciplinary research.