Zhanpeng Jin

Thermodynamic assessment of the CaOB2O3 system

Abstract The CaO-B 2 O 3 pseudo-binary system has been assessed thermodynamically. A two-sublattice ionic solution model, (Ca +2 )p(O −2 ,BO 3 −3 ,B 4 O 7 2,B 3 O 4.5 ) Q was adopted to describe the liquid phase. All the solid phases are treated as stoichiometric compounds. A set of parameters consistent with most of the experimental data on both phase diagram and thermodynamic properties was obtained by using the CALPHAD technique. A comparison between the calculated results and experimental data as well as a previous assessment is presented.

Thermodynamic calculation of the ZrO2-YO1.5-CaO phase diagram

Thermodynamic assessments of the ZrO2-YO1.5 and YO1.5-CaO systems have been conducted and combined with the previous evaluation of the ZrO2-CaO system to describe the ZrO2-YO1.5-CaO system by means of Bonniers equation. The binary and ternary solution phases are described by a simple substitutional solution model. All binary compounds are modeled as stoichiometric compounds. Comparisons between calculated isothermal phase diagrams and available experimental data demonstrate that the calculations satisfactorily account for reliable experimental data and no ternary interaction parameter is necessary for the description of the ZrO2-YO1.5-CaO system. The need for a better knowledge of the CaZrO3-YO1.5 system is stressed.

Thermodynamic assessment of the BaO - TiO2 quasibinary system

Abstract Experimental data from the literature on the BaO-TiO 2 quasibinary system have been evaluated to assess the thermodynamic parameters of all the stable phases by means of the CALPHAD (CALculation of PHAse Diagram) method. The two-sublattice ionic solution model was used to describe the liquid phase, while the compound energy model was applied to describe the high-temperature forms of BaTiO 3 . Other compounds were treated as stoichiometric phases. The assessment was conducted using the Thermo-calc software package and a set of parameters was given. Calculated equilibrium phase diagrams and thermochemical properties compared with the experimental data are presented. There is a good agreement between the calculations and the experimental data. Some contradictions are pointed out and discussed.

Thermodynamic modeling of the Al–Sr system

The Al–Sr system is thermodynamically assessed by means of the CALPHAD (CALculation of PHAse Diagrams) method. Three stoichiometric compounds, Sr8Al7, SrAl2, and SrAl4, are included in the modeling. The terminal solid solutions, (bSr), (aSr), and (Al), are described to show negligible solubilities. A Redlich–Kister formula is used to describe the liquid phase. A set of consistent thermodynamic parameters is obtained by considering reliable experimental data. The calculated phase diagram and thermodynamic properties agree reasonably with the corresponding experimental data.

Prediction of formation of intermetallic compounds in diffusion couples

Formation of intermetallic compounds (IMCs) at the interface between two metals during soldering processing exerts much influence on the electrical and mechanical performance of integrate circuits (ICs). Considering both of the thermodynamic and kinetic factors (including nucleation and growth) on phase formation, a new model capable of predicting phase formation sequence at the interface between two metals with different structures has been proposed in this work. Application of this new model on the interfacial reactions between pure elemental pairs of metals such as Ni/Sn, Cu/In, Cu/Sn, and Co/Sn at different temperatures shows good agreement between predictions by this model and experimental observations.

An assessment of the AlO1.5-YO1.5 system

Abstract The AlO 1.5 -YO 1.5 system has been assessed using the CALPHAD technique. The liquid phase was described by a subregular substitutional solution model. All solid phases were treated as stoichiometric compounds. A consistent set of parameters describing the Gibbs energy of the phases was obtained by a computerized least squares method. Stable and metastable phase equilibria were calculated with the optimized parameters. Comparisons between the assessed and experimental data are presented.

Thermodynamic assessment of the Au-Ti system

Abstract The Au-Ti binary system has been reassessed using the CALPHAD technique. With the set of optimized parameters a calculated phase diagram, which agrees well with all the experimental information including phase diagram and new thermodynamic data, has been obtained. It is shown that further experimental details are required especially for the liquidus and solidus of βTi at high temperature as well as the transformations between TiAu allotropes

Thermodynamic description of BaO-SrO-TiO2 system

Abstract The thermodynamic descriptions of the BaO-SrO-TiO2 pseudo-ternary and its lower order sub-systems have been made by critically evaluating all available experimental data. The temperature-dependent Gibbs energies of perovskite structural phases were evaluated to be relative to the standard element reference state (SER). The substitutional solution model for liquid and line compounds, Neumann-Kopp Rule for stoichiometric compounds were adopted. A set of self-consistent parameters reproducing most of the corresponding experimental data has been obtained.

Thermodynamic assessment of the HfO2-MgO system

Abstract HfO 2 -MgO quasibinary system has been assessed thermodynamically by means of CALPHAD method. The phase diagram consistent with experimental information was obtained with an optimized set of 10 parameters for different phases. Further information is necessary on the lower limit of fluorite-type solid solution as well as the stability range of the ordered phase Mg 2 Hf 5 O 12 .

Thermodynamic Optimization of the Na 2 O-B 2 O 3 Pseudo-Binary System

The Na2O-B2O3 system is thermodynamically optimized by means of the CALPHAD method. A two-sublattice ionic solution model, (Na+1)P(O−2,BO3−3,B4O7−2,B3O4.5)Q, has been used to describe the liquid phase. All the solid phases were treated as stoichiometric compounds. A set of thermodynamic parameters, which can reproduce most experimental data of both phase diagram and thermodynamic properties, was obtained. Comparisons between the calculated results and experimental data are presented.