Graduate Seminar Series
September 23, 2022
12:20 p.m. ET
Porter Hall - Room 100
Oxidation mechanisms of developmental refractory materials
Materials for long term application in high temperature oxidizing environments have relied on formation
of protective Cr 2 O 3 , Al 2 O 3 , and SiO 2 scales. These materials are typically limited to use temperatures of
1500 degrees C and below. A need exists for refractory materials for use in oxidizing environments at
temperatures exceeding 1500 degrees C. Refractory alloys and ultra-high temperature ceramics have been
proposed for these use conditions. While much effort has been expended to develop these materials, a
lack of both fundamental understanding of their oxidation mechanisms and methods to improve their
oxidation resistance exists. In this presentation, current status of oxidation studies on refractory metals,
refractory carbides, and refractory multiple principal element alloys will be reviewed. Specifically,
metals, alloys, and carbides containing, Ti, Zr, Hf, Nb, and Ta were studied. Short term oxidation studies
(2 minutes to 20 hours) were conducted at temperatures between 900 and 1600 degrees C in reduced oxygen
partial pressures (1% O 2 /balance argon) using either resistive heating or thermogravimetric analysis.
Weight change, oxide thickness, and material consumption rates in conjunction with microstructural
characterization were used to elucidate effects on oxidation mechanisms including oxygen dissolution in
alloys, CO(g) production from carbides, and complex oxide formation from multicomponent materials.
Presented by Elizabeth Opila
Elizabeth Opila is the Rolls-Royce Commonwealth Professor of Materials Science and Engineering and
Director of the Rolls-Royce University Technology Center for Advanced Materials Systems at the
University of Virginia in Charlottesville, where she has been since 2010. Her current research focus
includes understanding thermodynamic and kinetic mechanisms for material degradation in extreme
environments, development of life prediction methodology based on understanding of fundamental high
temperature chemical reaction mechanisms, and materials development for protection of materials from
extreme environments. Prof. Opila received her BS in Ceramic Engineering from the University of
Illinois, her MS in Materials Science from the University of California Berkeley, and her PhD in
Materials Science from the Massachusetts Institute of Technology. She is Fellow of the American
Ceramic Society and the Electrochemical Society and recipient of the 2021 American Ceramic Society’s
Arthur L. Friedberg Award. She has over 130 publications and is coinventor on six patents.