In this work,the CALPHAD (Computational Phase Diagram) method was used to model the Gibbs free energy of each phase of the Pt-Pd system,and two sets of thermodynamic parameters were obtained by fitting the thermodynamic experimental data. These parameters can be applied to the simulation of phase composition,phase transformation,Scheil solidification path,and microstructure evolution,etc. They are also conducive to the design of high-performance alloy composition. In response to the debate about the existence of the Face Center Cubic (Fcc) miscibility gaps in the Pt-Pd system,the Parrot module in the Thermo-calc software was utilized to thermodynamically optimize the two cases separately,based on the latest experimental data. The Gibbs free energy was calculated by optimizing the two sets of self-consistent thermodynamic parameters and the results were then compared. It has been confirmed that the miscible gap is in a metastable state. The FCC metastable phase diagram provides phase composition information in the miscible gap range,and the thermodynamic properties predicted by the equilibrium phase diagram are highly consistent with the experimental data.
关键词
相图/热力学优化/混溶间隙/Pt-Pd体系
Key words
diagram phase/thermodynamic optimization/miscibility gap/Pt-Pd system
维普
万方数据