CALPHADthermodynamische

CALPHAD, an acronym for CALculation of PHAse Diagrams, is a method and a database approach used to model and predict the thermodynamic properties of materials and their phase diagrams. It originated in the mid-20th century and has become a cornerstone of computational materials science. The core of CALPHAD involves developing thermodynamic databases for multi-component systems. These databases are constructed using experimental data, first-principles calculations, and thermodynamic models that describe the Gibbs free energy of various phases as a function of temperature, pressure, and composition.

The CALPHAD method allows scientists and engineers to predict phase equilibria, such as solid solutions, intermetallic compounds, and liquid phases, under different conditions without conducting extensive experiments. This predictive capability is crucial for designing new alloys, optimizing manufacturing processes, and understanding material behavior under extreme conditions. The thermodynamic models typically employ empirical parameters that are fitted to experimental phase diagram information and thermodynamic data. These models are often based on the CALPHAD type of Gibbs energy functions.

Applications of CALPHAD are widespread, spanning various industries including metallurgy, ceramics, and geochemistry. It is instrumental in the development of steels, aluminum alloys, superalloys, and functional materials. The accuracy of CALPHAD predictions relies heavily on the quality and completeness of the underlying thermodynamic databases. Ongoing research focuses on improving the models, expanding the databases to more complex systems, and integrating CALPHAD with other computational tools for a more comprehensive materials design approach.