Experimental study and thermodynamic modelling of the Cu-Fe-Si-U sub-systems

JOURNAL OF ALLOYS AND COMPOUNDS

卷:799

Article

Soldi, L.¹  Gosse, S.¹  Laplace, A.²  Bonnaillie, P.³  Schorne-Pinto, J.¹  Roskosz, M.⁴ 

[1] Univ Paris Saclay, DEN Serv Corros & Comportement Mat Leur Environm, CEA, F-91191 Gif Sur Yvette, France

[2] CEA Marcoule, DEN Serv Etud Vitrificat & Proc Hautes Temp SEVT, D765, F-30200 Chusclan, France

[3] Univ Paris Saclay, CEA, DEN Serv Rech Met Phys SRMP, F-91191 Gif Sur Yvette, France

[4] Sorbonne Univ, UMR CNRS 7590, Inst Mineral Phys Mat & Cosmochim, Museum Natl Hist Nat, F-75005 Paris, France

关键词: Calphad;    Copper;    Liquid-solid reactions;    Miscibility gap;    Phase diagrams;    Thermodynamic modelling;   

DOI  :  10.1016/j.jallcom.2019.05.294

来源: Elsevier

【 摘 要 】

The vitrification is a possible treatment for the conditioning of the metallic Long-Lived Intermediate-Level nuclear waste. This process is characterised by the presence of immiscible oxide and metallic liquids that react each other. A thermodynamic model using the Calphad method is then required to predict the composition of the treated waste and the speciation of uranium in this complex system. The quaternary Cu-Fe-Si-U is chosen as the most representative to describe the metallic liquids that appear at high temperature. Key sub-systems of this quaternary are experimentally investigated and thermodynamically modelled. The description of the liquidus in the Si-rich corner of the binary Cu-Si is improved. The Cu-U is assessed with the Calphad method for the first time; it is characterised by a large miscibility gap in the liquid phase. Some new ternary isotherms of the ternary Cu-Fe-Si are then proposed: a large liquid miscibility gap appears also in this system in agreement with the observed behaviour of the metallic liquid during the experimental investigations. The Cu-Si-U system is characterised by three ternary intermetallic compounds: CuSiU, Cu2Si2U and Cu4Si4U3. A first description is proposed, but more data are still required to improve the thermodynamic modelling of this system. (C) 2019 Elsevier B.V. All rights reserved.

【 授权许可】

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