MSE Seminar: Kelly Nygren (Cornell CHESS)

Description

Research on engineering alloys for structural applications remains as vital as ever. While new alloying strategies and advanced manufacturing techniques continue to emerge, material adoption processes still rely heavily – often exclusively – on empirical data. Even well-established alloys require improved models and deeper understanding to adapt to evolving design requirements, raw material availability, and supply chain constraints. High-energy X-rays at synchrotron sources like CHESS provide a non-destructive means to characterize a material’s microstructural and micromechanical state across critical length scales – from atomic arrangements to grain structures to continuum-scale polycrystalline behavior. The high flux from synchrotron sources enables time-resolved measurements that track a material’s response across timescales (as short as tens of nanoseconds) and facilitates rapid characterization over large regions of a sample in any given state. When combined with electron microscopy and materials modeling, multi-modal synchrotron datasets offer invaluable insights, shedding light on the mechanisms that link an alloy’s microstructure to its real-world performance. This talk will introduce state-of-the-art measurements at CHESS’s structural beamlines and highlight recent work using high-energy X-ray diffraction microscopy to identify early damage accumulation associated with fatigue crack initiation in nickel superalloys for aerospace applications. Additionally, it will explore how these once academic tools are being adapted for industrial applications, playing a critical role in materials design, processing, and performance model validation.
 

Bio: Kelly Nygren is the lead staff scientist at the Structural Materials Beamline at the Cornell High Energy Synchrotron Source (CHESS), combining her passion for understanding the performance of current and next-generation engineering alloys with applied problems. SMB is part of the Materials Solutions Network at CHESS, an Air Force Research Laboratory funded subfacility dedicated to targeting the most urgent and promising opportunities facing the Department of Defense and their Original Equipment Manufacturers.  Kelly earned her B.S. in 2011 and Ph.D. in 2016 from the University of Illinois Urbana-Champaign in materials science and engineering. In her graduate work, advanced electron microscopy tools across length scales were used to illuminate deformation and fracture pathways of engineering alloys in extreme environments. Her postdoc at the University of Wisconsin Madison extended these studies into corrosion and radiation degradation of alloys. Challenged with how to interface mechanistic understandings from electron microscopy with macroscopic models, she joined the Cornell community as a CHESS postdoc seeking to bridge these length scales with synchrotron X-ray diffraction. In her current role, she continues to combine these complementary modalities to target fundamental mechanisms of deformation in polycrystalline alloys, especially under fatigue and extreme conditions.