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Fundamentals of Pellet-Clad Debonding

Dingreville, Remi P.; Hattar, Khalid M.; Boyle, Timothy J.; Monterrosa, Anthony M.; Barr, Christopher M.; Weck, Philippe F.; Juan, Pierre-Alexandre J.

This project focused on providing a fundamental mechanistic understanding of the complex degra- dation mechanisms associated with Pellet/Clad Debonding (PCD) through the use of a unique suite of novel synthesis of surrogate spent nuclear fuel, in-situ nanoscale experiments on surrogate interfaces, multi-modeling, and characterization of decommissioned commercial spent fuel. The understanding of a broad class of metal/ceramic interfaces degradation studied within this project provided the technical basis related to the safety of high burn-up fuel, a problem of interest to the DOE.

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TYPE SAND Report YEAR 2018
OSTIDOI

High temperature irradiation induced creep in Ag nanopillars measured via in situ transmission electron microscopy

Scripta Materialia

Jawaharram, Gowtham S.; Price, Patrick M.; Barr, Christopher M.; Hattar, Khalid M.; Averback, Robert S.; Dillon, Shen J.

Irradiation induced creep (IIC) rates are measured in compression on Ag nanopillar (square) beams in the sink-limited regime. The IIC rate increases linearly with stress at lower stresses, i.e. below ≈2/3 the high temperature yield stress and parabolically with pillar width, L, for L less than ≈300 nm. The data are obtained by combining in situ transmission electron imaging with simultaneous ion irradiation, laser heating, and nanopillar compression. Results in the larger width regime are consistent with prior literature.

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TYPE Journal Article YEAR 2018
ScopusOSTIDOI

Grain boundary phase transformations in PtAu and relevance to thermal stabilization of bulk nanocrystalline metals

Journal of Materials Science

O'Brien, Christopher J.; Barr, Christopher M.; Price, Patrick M.; Hattar, Khalid M.; Foiles, Stephen M.

There has recently been a great deal of interest in employing immiscible solutes to stabilize nanocrystalline microstructures. Existing modeling efforts largely rely on mesoscale Monte Carlo approaches that employ a simplified model of the microstructure and result in highly homogeneous segregation to grain boundaries. However, there is ample evidence from experimental and modeling studies that demonstrates segregation to grain boundaries is highly non-uniform and sensitive to boundary character. This work employs a realistic nanocrystalline microstructure with experimentally relevant global solute concentrations to illustrate inhomogeneous boundary segregation. Furthermore, experiments quantifying segregation in thin films are reported that corroborate the prediction that grain boundary segregation is highly inhomogeneous. In addition to grain boundary structure modifying the degree of segregation, the existence of a phase transformation between low and high solute content grain boundaries is predicted. In order to conduct this study, new embedded atom method interatomic potentials are developed for Pt, Au, and the PtAu binary alloy.

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TYPE Journal Article YEAR 2017
OSTIDOI
Results 26–50 of 52
Results 26–50 of 52