Thermodynamic modeling of materials with the CALPHAD method

Thermodynamic calculations allow predictions about phase formation in materials during thermal processes, both during their manufacturing and under application conditions. The CALPHAD method (CALculation of PHAse Diagrams) enables the modeling of application-relevant materials beyond binary and ternary systems (e.g. Fe-Ni-Cr-Al-Y as a high-temperature alloy and Al-Mo-Nb-Ta-Ti-Zr as a high-entropy alloy) as well as the computer-aided simulation of their thermodynamic properties under defined conditions, e.g. chemical composition and temperature.

Simulations can be designed both in thermodynamic equilibrium (heat treatment) and for processes with rapid solidification, e.g. beam-based additive manufacturing or melt spinning.

The software used is Thermo-Calc with databases for relevant material systems, e.g. lightweight and high-temperature alloys, steels, innovative high-entropy alloys, and metal hydrides for hydrogen storage.

Fraunhofer IFAM Dresden has extensive capabilities and expertise for the experimental validation of simulation results, e.g. thermal analysis, heat treatment, metallography, scanning electron microscopy, and process analysis.

Examples of applications:

• Calculation of melting and transformation temperatures for heat treatment processes
• Prediction of material density in the context of material development and optimization
• Simulation of the volume content of precipitation phases as a basis for hardening processes and application-optimized strength properties

Customer benefits:

• Shortens development times and costs by minimizing experimental effort
• Enables the optimization of manufacturing processes/chains by deriving optimal parameters (e.g. heat treatment temperatures as low as possible) and thus high economic efficiency
• Promotes understanding of structural changes in the material and the resulting changes in properties during production and in use
• Allows predictions about the interaction of materials with environmental media and thus estimates of their suitability under the intended manufacturing and application conditions