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Title: Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir

Abstract

Experimentally, it is known that very small amounts of thorium and/or cerium added to iridium metal form a precipitate, Ir5Th / Ir5Ce, which improves the high temperature mechanical properties of the resulting alloys. We demonstrate that there are low-energy configurations for nano-scale precipitates of these phases in Ir, and that these coherent arrangements may assist in producing improved mechanical properties. One precipitate/matrix orientation gives a particularly low interfacial energy, and a low lattice misfit. Nanolayer precipitates with this orientation are found to be likely to form, with little driving force to coarsen. The predicted morphology of the precipitates and their orientation with the matrix phase provide a potential experiment that could be used to test these predictions.

Authors:
 [1];  [1];  [1]
  1. ORNL
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1121796
DOE Contract Number:  
DE-AC05-00OR22725
Resource Type:
Journal Article
Journal Name:
Philosophical Magazine
Additional Journal Information:
Journal Volume: 94; Journal Issue: 9; Journal ID: ISSN 1478--6435
Country of Publication:
United States
Language:
English

Citation Formats

Morris, James R, Averill, Frank, and Cooper, Valentino R. Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir. United States: N. p., 2014. Web. doi:10.1080/14786435.2013.875233.
Morris, James R, Averill, Frank, & Cooper, Valentino R. Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir. United States. https://doi.org/10.1080/14786435.2013.875233
Morris, James R, Averill, Frank, and Cooper, Valentino R. 2014. "Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir". United States. https://doi.org/10.1080/14786435.2013.875233.
@article{osti_1121796,
title = {Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir},
author = {Morris, James R and Averill, Frank and Cooper, Valentino R},
abstractNote = {Experimentally, it is known that very small amounts of thorium and/or cerium added to iridium metal form a precipitate, Ir5Th / Ir5Ce, which improves the high temperature mechanical properties of the resulting alloys. We demonstrate that there are low-energy configurations for nano-scale precipitates of these phases in Ir, and that these coherent arrangements may assist in producing improved mechanical properties. One precipitate/matrix orientation gives a particularly low interfacial energy, and a low lattice misfit. Nanolayer precipitates with this orientation are found to be likely to form, with little driving force to coarsen. The predicted morphology of the precipitates and their orientation with the matrix phase provide a potential experiment that could be used to test these predictions.},
doi = {10.1080/14786435.2013.875233},
url = {https://www.osti.gov/biblio/1121796}, journal = {Philosophical Magazine},
issn = {1478--6435},
number = 9,
volume = 94,
place = {United States},
year = {Wed Jan 01 00:00:00 EST 2014},
month = {Wed Jan 01 00:00:00 EST 2014}
}