He, P.

Hoffmann, J.

Möslang, A.

Rieth, M.

English

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KIT - University of the State of Baden-Wuerttemberg and National Research Center of the Helmholtz Associationwww.kit.eduInstitute for Applied MaterialsHerrmann-von-Helmholtz-Platz 176744 Eggenstein-Leopoldshafenhttp://www.kit.eduProductionPreparationEXAFS / XANES ExperimentsJan Hoffmann*, Anton Möslang, Pei He, Michael RiethKarlsruhe Institute of Technology, Institute for Applied Materials IAM-AWP, Karlsruhe, GermanyThis work was carried out in the framework of the European Fusion Development Agreement.  The authors acknowledge the European Synchrotron Radiation Facility (ESRF) in Grenoble for opportunity of the measurements. The  chemical analysis group of KIT / IAM-AWP is aknowledged for the analysis of the impurities / oxygen content.*contact:Jan Hoffmanne-mail: j.hoffmann@kit.eduphone: +49 (0) 721 6082 3476Validation of the production of ODS alloys by extended x-ray absorption fine structure (EXAFS)The aim of this work is the investigation on the transformation of Yttrium during the production process of ODS alloys. The dissolution during mechanical alloying and the re-precipitation during annealing treamtments are studied by extended x-ray absorption fine-structure (EXAFS) and x-ray near-edge-spectroscopy (XANES).The precipitation of oxi-de-clusters takes place at high temperatures. Only minor differences can be observed after annealing at 800°CMechanical alloying of the powders with Y2O3 causes a shift of the XANES spectrum.The curve does not match the Y2O3-refe-rence anymore. The shift can be corre-lated with the dissolu-tion of yttrium during the mechanical alloy-The height for the Y-O co-ordination shell increased after annealing at 1000°C. Precipitation of the oxi-de-clusters has occured.The difference DR for the Y-Y neighbor in Y2O3 and pure Y can be used to distinguish between the oxidized and pure (me-tallic) state of Yttrium.The precipitation is fini-shed. A full peak height matching the Y-O coordi-nation state in Y-Ti-O clus-ters can be observed.1. Mechanical alloying of pre-alloyed (ferritic) steel powder with Y2O3.2. Annealing of the powders in a vacuum furnace at 800°C, 1000°C and 1100°C for 2 hours3. Y-K edge (17.038 keV) was used for all experiments at ESRF in Grenoble4. Powder pellets were pressed for EXAFS measurements (in Fluorescence Mode)5. Pure Y-foil and Y2O3 powder were used as reference samples (measured in Transmission Mode)Fe13Cr1W0.3Ti+Y2O3Annealing of the powders 800°C / 1000°C / 1100°Cmechanical alloying800°C1000°C1100°Cenergy (keV)ing process.The linear combination fit of the experimental data with the two reference spectra can be used to calculate the ratio of dissolved Yttrium in the matrix:Specimen 24has-milled800°Cannealed1000°Cannealed1100°CannealedYdissolved (%) 13.7 99.9 97.6 0

Validation of the production of ODS alloys by extended x-ray absorption fine structure (EXAFS)

https://publikationen.bibliothek.kit.edu/220093438/3816407

Validation of the production of ODS alloys by extended x-ray absorption fine structure (EXAFS)

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