About this Abstract |
Meeting |
2021 TMS Annual Meeting & Exhibition
|
Symposium
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Materials for High Temperature Applications: Next Generation Superalloys and Beyond
|
Presentation Title |
Kinetics of Grain Boundary Segregation in an Ir Alloy* |
Author(s) |
Dean Pierce, Govindarajan Muralidharan, Jon Poplawsky, George Ulrich |
On-Site Speaker (Planned) |
Dean Pierce |
Abstract Scope |
Iridium (Ir) alloy DOP-26 (Ir-0.3W-0.006Th-0.005Al wt.%) is used as a fuel cladding material in radioisotope thermoelectric generators for space applications owing in part to its excellent high temperature impact ductility. Previous work has shown that additions of 20 to 1500 wppm of silicon (Si) to DOP-26 resulted in grain boundary Si concentrations of up to ~60 times bulk levels, contributing to loss of impact ductility. The focus of the present work is to understand the effect of temperature and time on the co-segregation behavior of both Si and Th to grain boundaries in Ir-alloys. Auger Electron Spectroscopy on in-situ fractured specimens and atom probe tomography was used to characterize grain boundary segregation. Effects of composition and temperature on the observed kinetics of segregation to grain boundaries will be discussed. |
Proceedings Inclusion? |
Planned: |
Keywords |
High-Temperature Materials, |