1. Direct sintering of UO2+x oxides prepared under hydrothermal conditions
- Author
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Jérôme Maynadié, Nicolas Clavier, Nicolas Dacheux, Jérémie Manaud, Xavier Le Goff, Renaud Podor, Interfaces de Matériaux en Evolution (LIME), Institut de Chimie Séparative de Marcoule (ICSM - UMR 5257), Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Etude de la Matière en Mode Environnemental (L2ME), Systèmes HYbrides pour la Séparation (LHyS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Ecole Nationale Supérieure de Chimie de Montpellier (ENSCM)-Institut de Chimie du CNRS (INC)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
Morphology (linguistics) ,Materials science ,Sintering ,02 engineering and technology ,[CHIM.INOR]Chemical Sciences/Inorganic chemistry ,01 natural sciences ,Hydrothermal circulation ,chemistry.chemical_compound ,0103 physical sciences ,Materials Chemistry ,Hydrothermal synthesis ,Uranium oxide ,Microstructure ,010302 applied physics ,[CHIM.MATE]Chemical Sciences/Material chemistry ,Actinide ,Sintering map ,021001 nanoscience & nanotechnology ,chemistry ,Yield (chemistry) ,Dilatometry ,Ceramics and Composites ,0210 nano-technology ,Nuclear chemistry - Abstract
International audience; The sintering of uranium oxide powders prepared by hydrothermal conversion of oxalates was studied. A dilatometric study first showed that among the synthesis conditions, only the pH largely impacted the densification, notably through the powders morphology. Three samples (single crystals-pH = 1, microspheres-pH = 2 and nano-powders-pH = 8) were further selected to study their sintering behaviour. Densitometric and granulometric data then allowed establishing sintering maps. For single crystals and microspheres, densities above 96%TD were obtained at 1700°C. In contrast, only 2 to 8 hours at 1500°C were needed to yield comparable results for nano-powders. These observations confirm that the hydrothermal conversion of oxalates can be considered as a promising route for the synthesis of actinide oxides, which can subsequently be sintered directly.
- Published
- 2021