Thermodynamic Assessments Of Phase Diagrams In Partial Pu-based Alloys

Nuclear energy is an important kind of new energy to actualize the development of human society.However,due to the rigorous restriction of the experimental conditions,the traditional trial and error method is not useful for the investigation of the nuclear materials.Thus,the developing of the thermodynamic design system of nuclear material is very important for designing high-powered nuclear materials based on the available experimental information of the phase diagrams and thermodynamic data.Pu-based alloys are the vital part of nuclear materials.In this work,thermodynamic calculations(CALPHAD) on the phase equilibria of partial Pu-based systems were carried out,and the thermodynamic database was developed.The thermodynamic database is described as follows:(1)Thermodynamic description of the Pu-X(X:Mg,Cu,Be,Cd,Bi,Mn,Nb,Mo, Cr,Ta,Re,W,Yb) binary systems were optimized by using the CALPHAD method based on critically evaluated experimental data.Calculated results from the obtained thermodynamic parameters were in agreement with the available experimental data.(2)Based on the optimized parameters in this work or literature for the Pu-X(X: Nb,Cr,Mo) and C-X(X:Pu,Nb,Cr,Mo) binary systems,the Pu-C-X(X:Nb,Cr,Mo) ternary systems were assessed according to the experimental data.The calculated phase equilibria and thermodynamic properties were in good agreement with the experimental data.(3)By combining with the optimized parameters in this work or literature for the Pu-X(X:Cr,Mg,Nb) and U-X(X:Pu,Cr,Mg,Nb) binary systems,the Pu-U-X(X: Cr,Mg,Nb) ternary systems were calculated.The partial thermodynamic database of(U,Th,Pu)-based nuclear alloys was successfully developed on the basis of the present work and previous research,which will provide powerful guide on the design of the new nuclear materials.