2012 — 2015 |
Yang, Judith (co-PI) [⬀] Gleeson, Brian |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Oxide Evolution Dynamics and Stability in Harsh Environments @ University of Pittsburgh
The research objective of this grant is to gain a detailed fundamental understanding of the complex interplay between the thermodynamics and kinetics governing early-stage surface-oxidation processes in single- and multi-oxidant environments. The study will use advanced high-resolution techniques to allow in situ interrogation of reaction-product interfaces for elucidating structural, chemical, and defect developments. Specifically, Ni, Ni-Cr, and, later, Ni-Cr-Al alloys in 700-1100¢ªC environments containing O2, H2O, CO2, or some combination of these as primary oxidants will be systematically examined. While the central focus is to establish science-based approaches for developing and/or improving advanced high-temperature alloys and coatings used in the many harsh environments found in practice, the scientific understanding gained will also contribute to elucidating the collective and coupled behaviors of surface reactions in general.
If successful, this interdisciplinary collaborative effort will lead to new paradigms in the important field of gas-solid surface reactions, such as corrosion, catalysis, sensors, fuel cells, and synthesis for a variety of electronic, magnetic, medical, and optical devices. The study will contribute to national economic competitiveness (novel materials and technologies created), development of a competitive STEM workforce (training and mentorship of graduate students and post-docs, interdisciplinary courses), the participation of women and underrepresented minorities; high school community outreach (Pennsylvania Junior Academy of Science), and national security (sustainable energy, energy generation, enhanced aircraft design). Materials-related classes at all levels will be developed or modified in multiple departments driven by the need to introduce students to the latest developments in materials-centered research and technology. Examples of classes include Gas-Metal Reactions, Crystallography, Nanocharacterization, Transmission Electron Microscopy, and Introduction to Materials Science.
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0.951 |
2017 — 2020 |
Gleeson, Brian Wang, Guofeng [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Understanding and Predicting Properties and Performance of Additively Manufactured Nickel-Based Superalloys @ University of Pittsburgh
Additive manufacturing, or 3D Printing, offers tremendous opportunity for efficient, custom manufacturing of critical parts. This processing approach can be applied to Nickel-based superalloys, which are specialized materials that have excellent high-temperature strength and good oxidation resistance, and hence are used in a wide range of technologies and applications. This award supports research to understand the fundamental relationships between processing and performance which will allow development of optimal additive manufacturing processes to fabricate nickel-based superalloy parts. An optimal process will enable the additively manufactured nickel-based superalloys to have excellent resistance to surface damage by high temperature oxidation while also retaining superior strength. Additively manufactured alloys have potential application in aerospace, automotive, biomedical, energy, and chemical industries. The results from this research therefore have the potential to benefit the U.S. economy and enhance manufacturing capabilities. Moreover, the research results will be incorporated into curriculum enhancement, student training, industrial collaboration, and an educational outreach program. Activities supported under this award will contribute to recruiting students from underrepresented groups to participate in research, and will positively impact higher education in science and engineering disciplines.
The combination of high strength and superior oxidation resistance of nickel-based superalloys make these materials good candidates for high-temperature applications. Additively manufactured nickel-based superalloys can possess mechanical properties comparable to those produced by conventional manufacturing techniques, but their resistance to high temperature oxidation is not comparable to conventionally manufactured components. To enable the application of additive manufacturing for high-temperature alloy fabrication, this research aims to understand and predict the processing-microstructure-oxidation relationships for additive manufactured nickel-based superalloys. The research team will fabricate nickel-based superalloys in layered forms using the laser engineered net shaping additive manufacturing technique, perform microstructural analysis on the alloys using electron microscopy, predict the solidification microstructure of the additive manufactured Ni alloys using numerical modeling techniques, and measure the high-temperature oxidation performance of additive manufactured Ni alloys via thermogravimetric analysis. This research will provide knowledge for determination of a critical cooling rate below which the superior high-temperature corrosion properties can be maintained in the additive manufactured nickel-based superalloys.
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0.951 |