Léo Moutin , Marc Josien , Michel Bornert , Christelle Duguay , Frédéric Adenot , Laurent Fayette , Renaud Masson
{"title":"二氧化铀陶瓷的导电性:500 ∘C以下从弱到强支化孔隙网络的影响(Exp)和数值模拟之外的影响","authors":"Léo Moutin , Marc Josien , Michel Bornert , Christelle Duguay , Frédéric Adenot , Laurent Fayette , Renaud Masson","doi":"10.1016/j.jnucmat.2024.155246","DOIUrl":null,"url":null,"abstract":"<div><p>We consider in this study three uranium dioxide ceramics whose porous network varies noticeably according to the manufacturing conditions. This porous network is characterized by a fine and elongated porosity which is made up of inter-granules pores but also of occluded pores which can be spotted at a much smaller scale. Thermal diffusivity measurements have been performed by a flash method on these ceramics at <span><math><mn>50</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C under different atmospheres but also up to <span><math><mn>500</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C under an argon and dihydrogen atmosphere. These measurements have shown marked differences in the thermal conductivities of the three ceramics, in particular a sharp degradation when the open porosity increases is reported. To understand the influence of these two families of porosities on the effective conductivity, a two-scale model has been developed. The effect of the occluded porosity is approximated using the Maxwell <span>[36]</span> model. The effect of the inter-granules porosity is evaluated by full-field numerical simulations performed on synthetic microstructures generated by the optimization process described in Moutin et al. <span>[41]</span>. Comparisons of model predictions to experimental results confirm the predominant role of the inter-granules porosity on the effective conductivity. Besides, it is shown that the Knudsen effect must be taken into account to accurately predict the variations in thermal conductivity of ceramics depending on the gas contained in the inter-granules pores at <span><math><mn>50</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C. Finally, the simulated conductivities of the ceramics are shown to predict temperatures effects up to <span><math><mn>500</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C.</p></div>","PeriodicalId":373,"journal":{"name":"Journal of Nuclear Materials","volume":null,"pages":null},"PeriodicalIF":2.8000,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Conductivity of UO2 ceramics: Effect of a weakly to strongly branched pore network up to 500 ∘C (exp) and numerical simulations beyond\",\"authors\":\"Léo Moutin , Marc Josien , Michel Bornert , Christelle Duguay , Frédéric Adenot , Laurent Fayette , Renaud Masson\",\"doi\":\"10.1016/j.jnucmat.2024.155246\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>We consider in this study three uranium dioxide ceramics whose porous network varies noticeably according to the manufacturing conditions. This porous network is characterized by a fine and elongated porosity which is made up of inter-granules pores but also of occluded pores which can be spotted at a much smaller scale. Thermal diffusivity measurements have been performed by a flash method on these ceramics at <span><math><mn>50</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C under different atmospheres but also up to <span><math><mn>500</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C under an argon and dihydrogen atmosphere. These measurements have shown marked differences in the thermal conductivities of the three ceramics, in particular a sharp degradation when the open porosity increases is reported. To understand the influence of these two families of porosities on the effective conductivity, a two-scale model has been developed. The effect of the occluded porosity is approximated using the Maxwell <span>[36]</span> model. The effect of the inter-granules porosity is evaluated by full-field numerical simulations performed on synthetic microstructures generated by the optimization process described in Moutin et al. <span>[41]</span>. Comparisons of model predictions to experimental results confirm the predominant role of the inter-granules porosity on the effective conductivity. Besides, it is shown that the Knudsen effect must be taken into account to accurately predict the variations in thermal conductivity of ceramics depending on the gas contained in the inter-granules pores at <span><math><mn>50</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C. Finally, the simulated conductivities of the ceramics are shown to predict temperatures effects up to <span><math><mn>500</mn><mspace></mspace><msup><mrow></mrow><mrow><mo>∘</mo></mrow></msup></math></span>C.</p></div>\",\"PeriodicalId\":373,\"journal\":{\"name\":\"Journal of Nuclear Materials\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":2.8000,\"publicationDate\":\"2024-06-27\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Nuclear Materials\",\"FirstCategoryId\":\"5\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0022311524003489\",\"RegionNum\":2,\"RegionCategory\":\"工程技术\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"MATERIALS SCIENCE, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Nuclear Materials","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0022311524003489","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"MATERIALS SCIENCE, MULTIDISCIPLINARY","Score":null,"Total":0}
Conductivity of UO2 ceramics: Effect of a weakly to strongly branched pore network up to 500 ∘C (exp) and numerical simulations beyond
We consider in this study three uranium dioxide ceramics whose porous network varies noticeably according to the manufacturing conditions. This porous network is characterized by a fine and elongated porosity which is made up of inter-granules pores but also of occluded pores which can be spotted at a much smaller scale. Thermal diffusivity measurements have been performed by a flash method on these ceramics at C under different atmospheres but also up to C under an argon and dihydrogen atmosphere. These measurements have shown marked differences in the thermal conductivities of the three ceramics, in particular a sharp degradation when the open porosity increases is reported. To understand the influence of these two families of porosities on the effective conductivity, a two-scale model has been developed. The effect of the occluded porosity is approximated using the Maxwell [36] model. The effect of the inter-granules porosity is evaluated by full-field numerical simulations performed on synthetic microstructures generated by the optimization process described in Moutin et al. [41]. Comparisons of model predictions to experimental results confirm the predominant role of the inter-granules porosity on the effective conductivity. Besides, it is shown that the Knudsen effect must be taken into account to accurately predict the variations in thermal conductivity of ceramics depending on the gas contained in the inter-granules pores at C. Finally, the simulated conductivities of the ceramics are shown to predict temperatures effects up to C.
期刊介绍:
The Journal of Nuclear Materials publishes high quality papers in materials research for nuclear applications, primarily fission reactors, fusion reactors, and similar environments including radiation areas of charged particle accelerators. Both original research and critical review papers covering experimental, theoretical, and computational aspects of either fundamental or applied nature are welcome.
The breadth of the field is such that a wide range of processes and properties in the field of materials science and engineering is of interest to the readership, spanning atom-scale processes, microstructures, thermodynamics, mechanical properties, physical properties, and corrosion, for example.
Topics covered by JNM
Fission reactor materials, including fuels, cladding, core structures, pressure vessels, coolant interactions with materials, moderator and control components, fission product behavior.
Materials aspects of the entire fuel cycle.
Materials aspects of the actinides and their compounds.
Performance of nuclear waste materials; materials aspects of the immobilization of wastes.
Fusion reactor materials, including first walls, blankets, insulators and magnets.
Neutron and charged particle radiation effects in materials, including defects, transmutations, microstructures, phase changes and macroscopic properties.
Interaction of plasmas, ion beams, electron beams and electromagnetic radiation with materials relevant to nuclear systems.