Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir

James R. Morris, Frank W. Averill, Valentino R. Cooper

Research output: Contribution to journalArticlepeer-review

2 Scopus citations

Abstract

Experimentally, it is known that very small amounts of thorium and/or cerium added to iridium metal form a precipitate, Ir5Th/Ir 5Ce, which improves the high-temperature mechanical properties of the resulting alloys. We demonstrate that there are low-energy configurations for nanoscale 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.

Original languageEnglish
Pages (from-to)991-1000
Number of pages10
JournalPhilosophical Magazine
Volume94
Issue number9
DOIs
StatePublished - Mar 24 2014

Funding

This material is published by permission of the Oak Ridge National Laboratory for the US Department of Energy under Contract No. DE-AC05-00OR22725. The US Government retains for itself, and others acting on its behalf, a paid-up, non-exclusive, and irrevocable worldwide license in said article to reproduce, prepare derivative works, distribute copies to the public, and perform publicly and display publicly, by or on behalf of the Government. We would like to thank E.P. George for useful discussion, and Hongbin Bei and Frederik Otto for comments on the manuscript. The research supported by the US Department of Energy (DOE), Basic Energy Sciences, Materials Sciences and Engineering Division. We also acknowledge computer time from the National Energy Research Scientific Computing Center (NERSC) of DOE. Lattice plots were made using VESTA [27] software.

FundersFunder number
U.S. Department of EnergyDE-AC05-00OR22725
Basic Energy Sciences
Division of Materials Sciences and Engineering

    Keywords

    • first-principles calculations
    • grain boundary segregation
    • interface structure
    • iridium
    • nanostructures

    Fingerprint

    Dive into the research topics of 'Theoretical studies of Ir5Th and Ir5Ce nanoscale precipitates in Ir'. Together they form a unique fingerprint.

    Cite this