Experimental Determination Of The Phase Diagram And Thermodynamic Calculation Of The Cu-based Key Ternary Systems

Copper and copper alloys are widely used in electricity,electron communication,aerospace,transportation and other fields due to their high electrical conductivity,high thermal conductivity,good mechanical properties,good corrosion resistance,etc.With the continuous progress of science and technology and the rapid development of electronic information industry,the performance requirements of copper alloy are higher and higher.How to obtain high quality copper alloy is a hot spot in recent years.Ag?Cr?Ni?Si?Co and W are the common alloying elements in the Cu-based alloys which can improve the properties of the alloy and obtain different copper alloys.In order to research and develop high-performance copper alloys,it is necessary to obtain accurate thermodynamic information of multi-component Cu-based and related alloy systems.In this paper,through the configuration of key alloys,the isothermal sections of Cu-Ag-Si,Cu-Cr-Ni,and Cu-Cr-Ag systems were measured by XRD and SEM/EDX,and the six ternary systems Cu-Ag-Si,Cu-Cr-Ni,Cu-Cr-Ag,Ni-Co-Re,Ni-Co-Ru and Ni-Re-W have been systematically investigated by means of CALPHAD(CALculation of PHAse Diagram)method and used the Thermo-Calc software.The main results are as following:(1)The phase equilibria of the Cu-Ag-Si system were investigated by a combination of key experiments and thermodynamic modeling.Eighteen ternary alloys were prepared to determine the isothermal sections at 500,600,and 700°C of the Cu-Ag-Si system by means of XRD and SEM/EDX.The solubilities of Ag in the Cu₁₉Si₆,Cu₁₅Si₄,Cu₅₆Si₁₁,and hcp(Cu Si)phases were measured.No ternary compound was found in this isothermal sections.Based on the experimental equilibria data from the present work,thermodynamic assessment of the Cu-Ag-Si system was calculated by the CALPHAD approach.The solution phases(Cu),(Ag),(Si),and hcp(Cu Si)were described using substitutional solution model and the binary phases Cu₁₉Si₆,Cu₁₅Si₄,and Cu₅₆Si₁₁ were modeled by the sublattice models.A set of self-consistent thermodynamic parameters of the Cu-Ag-Si system was obtained.The isothermal sections at 500,600,650,and 700°C,vertical sections at 10 and 20 at.%Ag,and liquidus projection were calculated.The reaction scheme of the Cu-Ag-Si system was constructed.The calculated results are in agreement with the experimental data from the present work and literature.(2)In order to obtain isothermal sections of Cu-Cr-Ag system at 500,600,650 and700?,11 key ternary alloy samples were prepared based on the experimental simulation complementary method.The isothermal sections of Cu-Cr-Ag system at 500,600,650 and 700?were measured by XRD and SEM/EDX.The solubility of the third element in the binary compound was obtained by determining the three-phase and two-phase regions,and no ternary compound was found in this ternary system.Based on the phase equilibrium data obtained in this work,the displacement solution model is used to describe the solution phase,and the thermodynamic description of Cu-Cr-Ag and the system is carried out by using phase diagram calculation method.A set of self-consistent and accurate thermodynamic parameters for Cu-Cr-Ag system are obtained.Most reliable experimental data can be consistent with the calculated results.(3)The phase equilibria of Cu-Cr-Ni system at 800 and 1000?were studied by combining key experiments with CALPHAD.The isothermal sections of Cu-Cr-Ni system at 800 and 1000?were measured by XRD and SEM/EDX.The solubility of the third element in the binary system was determined.No ternary compound was found.Based on the experimental phase equilibrium data in literature and this work,the solution phase is described by the displacement solution model,and the thermodynamic description of Cu-Cr-Ni system is carried out by phase diagram calculation method.A set of self-consistent and accurate thermodynamic parameters for Cu-Cr-Ni system are obtained,which are consistent with most reliable experimental data.(4)Based on the thermodynamic descriptions of the constitutive binary system and the experimental phase equilibrium data of the ternary system reported in the literature,the Ni-Co-Re,Ni-Co-Ru and Ni-Re-W systems have been evaluated using the CALPHAD approach.The solution phases fcc,bcc and hcp were described using substitutional solution model and the binary phases?(Re W)and?(Re3W)were modeled by the sublattice models.A set of self-consistent thermodynamic parameters of the Ni-Co-Re,Ni-Co-Ru and Ni-Re-W system was obtained.Some representative isothermal sections and liquid surface projections were calculated.By comparing with the experimental data,the calculated results were in agreement with the experimental data by the present modeling.Figure[36]table[13]reference[110]...