Thermodynamic Calculation And Experimental Study Of Ga-In-Pd System

Ga-In-Pd alloy has important application in many fields of science and technology,such as semiconductor,aerospace,automotive manufacturing,and medical treatment.It also has potential application in the preparation of graphene.The establishment of phase diagram database of Ga-In-Pd ternary alloy can lay an important foundation for the wide application of this alloy.The main work of this project is to do some thermodynamic calculation and experimental study of Ga-In-Pd ternary system,which provides reliable experimental data for the establishment of thermodynamic database of Ga-In-Pd ternary alloy.The major achievements of the present work are as follows:In this work,based on the experimental investigation of the phase equilibria from literatures,a set of self-consistent thermodynamic parameters are optimized by using CALPHAD method and Pandat software about thermodynamic calculation.The phase including Liquid and Fcc-Pd were treated as substitutional solution phases,of which the excess Gibbs energies were formulated with Redlich–Kister polynomial functions.GaPd2 is described by a(Ga,Pd)(Pd)2 two-sublattice model,which ignored the excess Gibbs free energy.All other solid phases are treated as being stoichiometric,of which the excess Gibbs energies were formulated with Neumann-Kopp rules.Combining with the thermodynamic parameters of the Ga-Pd binary systems optimized in the present work and the Ga-In and In-Pd binary systems cited from literature,the Ga-In-Pd ternary system was thermodynamic extrapolated by using CALPHAD method and Pandat software.In addition,we also calculated liquids projection and isothermal section of Ga-In-Pd ternary system at 300? and 500?.We prepared some long time annealing samples of Ga-In-Pd ternary alloy at 300? and 500?,of which the equilibrium phases were analyzed by scanning electron microscopy(SEM)and X-ray diffraction(XRD).Comparing with the isothermal cross section of 300? and 500? of the extrapolated Ga-In-Pd ternary system,we analyzed the experimental data.The calculated phase equilibria are in agreement with the experimental data partially.The phase transition of some Ga-In-Pd alloys during heating process was investigated by differential scanning calorimetry(DSC).Comparing with the calculated results,we analyzed the experimental data and proved the existence of some phase transition.