Study On The Phase Diagram And Thermodynamics Of The Ti-W-M(M=B,Si,Zr,Mo,Nb) And Cu-Nb-X(X=Ni,Si) System

Material design and new material development are hot topics in materials research,and phase diagrams and thermodynamic information of phase diagrams play a pivotal role in the field of materials research.This work mainly focuses on the basic research of material thermodynamics in the key material system of Ti alloy with important industrial application value.For engineering applications,the design-type experiment coupled phase diagram calculation(CALPHAD:CALculation of PHAse Diagram)is used to expand the thermodynamic database of Ti-based systems and provide effective thermodynamic information for material design and preparation.Through the study of several important Ti alloy systems selected in this work,and the analysis of several problems in current material thermodynamics research,the specific content and main points of this work can be summarized as follows:(1)A detailed literature data evaluation of the marginal binary and ternary systems of the Ti-WM(M=B,Si,Zr,Mo,Nb)system,based on the experimental data reported in the literature and the thermodynamics of the boundary binary system Description,using the CALPHAD method,the Ti-W-M(M=B,Si,Zr,Mo,Nb)was thermodynamically optimized,and a set of accurate descriptions of Ti-WM(M=B,Si,Zr,Mo,Nb)was obtained.The thermodynamic parameters of the system.At the same time,some representative isothermal cross-sections,vertical cross-sections,liquid-phase projections and solid-phase projections are calculated.The thermodynamic parameters obtained in this work can describe the experimental data well.(2)Using the method of coupling key experiments with CALPHAD,based on the experimental phase equilibrium data of Cu-Nb-M(M=Ni,Si)system reported in the literature,a systematic phase diagram thermodynamic study of the system was carried out.The equilibrium alloy method was used to prepare annealed alloy samples.With the aid of SEM/EDX and XRD analysis methods,the 700,800 and 900? isothermal sections of the Cu-Nb-Ni ternary system were measured.The experimental results show that the system has two highly soluble compounds and two three-phase regions.The Cu-Nb-Ni system was thermodynamically optimized by CAKPHAD method,and a set of thermodynamic parameters describing the system was obtained.The calculated isothermal section is consistent with the experimental data.(3)In order to obtain the 600? and 700? isothermal cross-sections of the Cu-Nb-Si ternary system,a total of 16 key alloys were prepared by coupling key experiments and the CALPHAD method,and the Cu-Nb-Si three alloys were determined by SEM/EDX,XRD and other analytical methods.The phase balance relationship of the element system.The analysis shows that the 600? and 700? isothermal cross-sections have similar phase relationships.At the same time,the solubility range of the ternary compound Cu₄Nb₅Si₄ was determined.Figure[89]table[11]reference[100]...