Influence of physical-chemical processing and operating environments on. Systems of interest: Ceramics Multi-layer coatings Corrosion Reactor systems

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1 Institute t for Materials Science DGM-Committee Thermodynamics, Kinetics and Phase Relations in Materials Hans Jürgen Seifert (TU Bergakademie Freiberg) Damian M. Cupid

2 A platform for the interdisciplinary discussion of experimental and theoretical techniques/issues in the equilibrium thermodynamics and kinetics of microstructural development Influence of physical-chemical processing and operating environments on stable and metastable microstructural development Systems of interest: Metal alloys Ceramics Multi-layer coatings Corrosion Reactor systems

3 Focus Points Experimental and theoretical methods used to generate thermodynamic data and construct phase diagrams Evaluation of ternary and higher-order systems (phase relations) Thermodynamic modelling of multi-component, multi-phase material systems Combination of thermodynamic modelling, reactor simulations and mathematical algorithms to describe multiphase materials kinetics on the micro and macro scales Developement of integrated thermodynamic-kinetic databases

4 1 st Focus Point Experimental and theoretical methods to generate thermodynamic and phase diagram data Calorimetry (DSC, Drop, Solution, Mixing) i Enthalpy, Heat Capacity Δ H, kj/mol y = 1 2 y = y = y = y = y = x Al Al Ni 1-y Cr y Knudsen-Effusion / Mass spectroscopy, EMF Chemical Potential Thermal Analysis (DTA, TGA, Dilatometry), X-ray diffraction, HT X-ray diffraction, Metallography, Chemical Analyisis, Phase diagrams

5 Equipment inventory in German-speaking countries Who has what? Which physical / thermodynamic properties can be measured? E t bli h d id li f i t l th d Established guidelines for experimetal methods Experimental procedures Data analysis

6 2 nd Focus Point Phase Diagram Evaluation for ternary and multi-component systems (Phase relations) using literature data as well as experimental data from committee members - Annual MSIT Conference (Materials Science International Team); - Publication of the critical evaluations: Landolt-Börnstein Handbooks, MSIT World Library, International Journal of Materials Research, Journal of Phase Equilibria and Diffusion

7 3 rd Focus Point Thermodynamic modelling of multi-component, multi-phase material systems Model developement Sublattice model Associate model Quasi-chemical Model Compund Energy Formalism

8 4 th Focus Point Combination of thermodynamic modelling, reactor simulations and mathematical algorithms to describe multiphase materials kinetics on the micro and macro scales Influence of environemental conditions Gas phase constitution Reactions with gas species Reactions with deposits Evaporation of gas species yttrium silicate SiO 2 Reactions within the coatings LPPS-coating CVD-SiC C/C-SiC substrate 200 µm Reactions between the coatings Reactions Substrate / Coating Reactions within the substrate

9 Molecular Dynamics Integration Ab-initio Calculations Experiments Thermodynamic Data, Phase diagrams Data for interfacial energies, Lattice Parameter, Elastic Constants Kinetic Data Reactor Simulation CALPHAD Scheil Solidification Thermodynamic Databases Database for interfacial energies, lattice parameter, elastic constants Kinetic Database Phase Field Method Sharp Interface Materials Properties Microstructural Development

10 Integration (Metastable) Phase Equilibira Direct Applications (Scheil-)Solidification and Diffusion Paths Combination with Combination with Combination with Steady State micro kinetics macro kinetics Reactor modelling Distribution into reaction steps The calculation results after one step is used for the next step Diffusion controlled solid state transformations Precipitate growth and decomposition Solid/solid interface reactions Dynamic macro scale processes involving fluid flow and thermal trasport Phase field method Alloy casting

11 5 th Focal Point Developement of integrated thermodynamic-kinetic databases Databases for applications oriented computer simulations of materials and materials processes Co-orperation with industry partners Interdisciplinary discussion platforms for basic and applications oriented research and developement in specified fields

12 5 th Focal Point Developement of integrated thermodynamic-kinetic databases Thermodynamic data (Gibbs Energy) Integrated Databases Interface energies, lattice parameter, elastic constants, Kinetics (Diffusion coefficients, Mobility) Calculation of: Physical Properties Interface energy Surface energy Viscosity Mechanical Properties Stress Microstructural development TTT- und CCT Diagrams Grain growth

13 Education University courses offered in materials thermodynamics, kinetics, and phase relations in multi-component systems Organization of DGM summer schools and short courses Computer aided thermodynamics PhD students with research topics in the field of heterogenous equilibria Calphad Phase field method Phase diagram determination ti

14 International Visibility Publication in international journals Organization of sessions at internatonal conferences Activities should be integrated into existing international co-orperations Alloy Phase Diagram International Commission, APDIC, Scientific Group Thermodata Europe (SGTE), ASM International: Phase Diagram Committee, TMS: Alloy Phases Committee Website