Dr. Michael Mills —Chair and Taine G. McDougal Professor of Engineering Department of Materials Science and Engineering at Ohio State University 

Abstract: Polycrystalline Ni-based superalloys are vital materials for disks in the hot section of aerospace and land-based turbine engines. Improving fuel efficiency and reducing greenhouse gas emissions compel increased performance at higher temperatures. In this presentation, two different approaches to improving high temperature strength and creep resistance are discussed. In the first approach, local ordered phases at stacking faults and microtwins can be accomplished by subtle changes to the alloy composition. Characterization that demonstrates this local phase transformation strengthening, and computational design for promoting this new mechanism will be discussed. In the second approach, oxide dispersion strengthening using a novel approach for introducing the oxide reinforcements has been demonstrated recently in work at NASA Glenn Research Center. The understanding of these benefits based on advanced characterization of the as-built and post-deformed substructures will also be presented. Pursuing possible synergies between these two approaches will also be discussed. 

Biography: Professor Mills earned his PhD in Materials Science and Engineering from Stanford University in 1985. Following research appointments at the EPFL and Sandia National Laboratories, he joined the Department of Materials Science and Engineering at The Ohio State University in 1994, becoming a full professor in 2000, McDougal Professor of Engineering in 2004, and has served as Department Chair since 2019. Mills' research explores the mechanical behavior of metals – including nickel-based superalloys, titanium, zirconium, aluminum, and high entropy alloys – with a focus on advanced electron microscopy investigations that elucidate deformation mechanisms. This understanding forms the foundation for fundamental models of behavior and is relevant to the industrial application of these materials. A Fellow of TMS and ASM, Mills has received numerous honors, including the Oleg D. Sherby Award from TMS, the Alexander von Humboldt Research Award, the Heyn Medal of Honor from the Deutsche Gesellschaft für Materialkunde, and an honorary doctorate from Ruhr University Bochum, Germany.