MSE Seminar: “Mechanical and Oxidation Behavior of Hf-25Ta-X Refractory Alloys”

Date/Time
Date(s) - 11/29/2022
3:00 pm - 4:00 pm

Location
Rhines Hall 125

Categories


Eric Payton, Ph.D.

Associate Professor, Department of Mechanical and Materials Science Engineering
University of Cincinnati

Dr. Eric Payton is an Associate Professor of Materials Science and Engineering in the Department of Mechanical and Materials Engineering at the University of Cincinnati. His laboratory addresses the sustainability of critical materials through fundamental research into alloy design, discovery, and processing. Our objective is to enable design engineers to balance performance with responsible resource utilization. Employing state-of-the-art computational and quantitative characterization techniques, his group seeks to lend insights into microstructure evolution during processing and chemo-mechanical environmental interactions in service, then use this knowledge to develop practical tools for predicting material properties.

Prior to joining the faculty of the University of Cincinnati in 2022, Dr. Payton served for five years as the Research Leader for the Metallic Materials and Processing Team at the Air Force Research Laboratory, Materials and Manufacturing Directorate. Before entering government service, he was an Assistant Professor of Materials Science and Engineering at the New York State College of Ceramics at Alfred University and held post-doctoral positions at both Ruhr University in Bochum, Germany and the Federal Institute for Materials Research and Testing (BAM) in Berlin, Germany. He obtained his doctorate in Materials Science and Engineering from The Ohio State University.

Dr. Payton’s colleagues suspect he would be a good addition to their trivia night team; however, his area of trivia mastery may be limited to turn-of-the-century musicians. Dr. Payton is an enthusiastic advocate of scientific collaboration, structured programming, learner-centered pedagogy, and vegetables.

Abstract

Recent work by Perepezko and Yang has indicated that Hf-27Ta forms an adherent and thermal-shock-resistant oxide (Hf6Ta2O17) during high-temperature oxidation, and Senkov et al have shown that additions of Mo and W while holding this Hf:Ta ratio can increase the high-temperature strength in this alloy system. The protective oxide is predicted using ab-initio calculations to also be formed preferentially at lower temperatures, <1500 degrees C. In the present work, we investigate the mechanical properties and oxidation behavior of arc-melted and hot isostatically pressed Hf-25Ta-5X alloys where X=Nb, Zr, Cr, W, Mo, or Mo+W at temperatures lower than 1500 degrees C. The observations are compared against other refractory complex concentrated alloys. It is observed that oxidation behavior of all Hf-25Ta-5X alloys investigated is inferior to Nb-18Ti-10W, and formation of a protective layer of Hf6Ta2O17 is not observed. The underlying reasons for this observation are explored and discussed.