Control of the final grain size distribution in a microstructure is of primary importance for superalloys which require narrow tolerance of mechanical properties, such as tensile strength, creep resistance, and fatigue resistance. Phenomena such as abnormal grain growth and unexpected recrystallization phenomena have historically hindered grain size control; however, a recently observed recrystallization mechanism known as Heteroepitaxial Recrystallization (HeRX) may provide answers. In this work, we demonstrate that HeRX is active under a wider range of processsing conditions than originally envisioned and illustrate its role in determining the final grain size distribution. This is potentially a new avenue of microstructural engineering, and there are promising hints that it may be able to be employed in many additional alloy systems.
Assistant Professor Victoria (Tori) Miller has been in the Department of Materials Science and Engineering at the University of Florida since September 2019. Prior to that, she spent two years as an Assistant Professor at North Carolina State University. She received her B.S.E. in Materials Science and Engineering from the University of Michigan in 2011 and completed her Ph.D. in the Materials Department at the University of California Santa Barbara in 2016. After graduate school, she worked for a year at UES, Inc. as a Research Scientist onsite in the Materials and Manufacturing Directorate of the Air Force Research Laboratory in Dayton, OH. She had also previously worked at Ford Motor Company Research and Development, Toyota Engineering and Manufacturing North America, and Lockheed Martin Aeronautics. Miller’s interests include defect and structural evolution in crystalline material and experimental characterization via advanced electron microscopy techniques. She is particularly focused on deformation processing of metals and the associated microstructural evolution, particularly texture evolution, recovery, and recrystallization. Her group’s primary focus is on “bridging the mesoscale gap” by linking macroscopic processing phenomena to micro- and nanoscale mechanisms, enabling the development of predictive material models for engineering applications.