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An investigation of the long-range and local structure of sub-stoichiometric zirconium carbide sintered at different temperatures.

ABSTRACT: ZrC1-x (sub-stoichiometric zirconium carbide), a group IV transition metal carbide, is being considered for various high temperature applications. Departure from stoichiometry changes the thermo-physical response of the material. Reported thermo-physical properties exhibit, in some cases, a degree of scatter with one likely contributor to this being the uncertainty in the C/Zr ratio of the samples produced. Conventional, methods for assigning C/Zr to samples are determined either by nominal stochiometric ratios or combustion carbon analysis. In this study, a range of stoichiometries of hot-pressed ZrC1-x were examined by SEM, XRD, Raman spectroscopy and static 13C NMR spectroscopy and used as a basis to correct the C/Zr. Graphite, amorphous, and ZrC1-x carbon signatures are observed in the 13C NMR spectra of samples and are determined to vary in intensity with sintering temperature and stoichiometry. In this study a method is outlined to quantify the stoichiometry of ZrC1-x and free carbon phases, providing an improvement over the sole use and reliance of widely adopted bulk carbon combustion analysis. We report significantly lower C/Zr values determined by 13C NMR analysis compared with carbon analyser and nominal methods. Furthermore, the location of carbon disassociated from the ZrC1-x structure is analysed using SEM and Raman spectroscopy.

SUBMITTER: Rana DBK

PROVIDER: S-EPMC7033217 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

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An investigation of the long-range and local structure of sub-stoichiometric zirconium carbide sintered at different temperatures.

Rana Dhan-Sham B K DBK Solvas Eugenio Zapatas EZ Lee William E WE Farnan Ian I

Scientific reports 20200220 1

ZrC<sub>1-x</sub> (sub-stoichiometric zirconium carbide), a group IV transition metal carbide, is being considered for various high temperature applications. Departure from stoichiometry changes the thermo-physical response of the material. Reported thermo-physical properties exhibit, in some cases, a degree of scatter with one likely contributor to this being the uncertainty in the C/Zr ratio of the samples produced. Conventional, methods for assigning C/Zr to samples are determined either by n ...[more]

PMID: 32080236

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Dataset Information

An investigation of the long-range and local structure of sub-stoichiometric zirconium carbide sintered at different temperatures.

Publications

An investigation of the long-range and local structure of sub-stoichiometric zirconium carbide sintered at different temperatures.

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