This course will give a detailed introduction to open-source computational thermodynamics and kinetics software based on the CALPHAD method. It will feature hands-on demonstrations in an interactive cloud environment and practical exercises that will enable attendees to calculate phase diagrams, simulate solid-state precipitation of alloys, and to propagate uncertainty in a given thermodynamic calculation.

PyCalphad

PyCalphad is a free and open-source Python library for calculating phase diagrams, designing thermodynamic models, and investigating phase equilibria within the CALPHAD method. It provides routines for reading thermodynamic databases and solving the multi-component, multi-phase Gibbs energy minimization problem. All Gibbs energy and property models in PyCalphad are described symbolically allowing the models to be customized or overridden by users at runtime without changing any of the PyCalphad source code. Calculation results from PyCalphad are returned as multidimensional datasets that make it easy to incorporate PyCalphad into any tool or workflow.

Kawin

Kawin is a new open-source implementation of the Kampmann–Wagner Numerical model of precipitation (concomitant nucleation, growth, and coarsening). An overview of the organization and capabilities of the program is provided, along with an outline of the constituent physics. Kawin is capable of simulating the bulk precipitation behavior of multiphase, multicomponent systems in response to complex heat treatments. The inclusion of native strain calculations enables Kawin to predict the influence of internal or external stress fields on precipitation, as well as track the evolution of precipitate geometry throughout the course of a heat treatment.

Course Goal: After following along with the provided exercises, attendees will complete the course with new tools in-hand, ready to take home.

Course Audience: Engineers and practitioners interested in learning more about open-source materials design tools.

The aim of the workshop is to follow data from their creation by assessments following the CALPHAD approach all the way to their use in industrial applications

Part 1 - May 26, 2024, 2 - 2:45 pm: DATA (Qing Chen and Mehdi Noori, Thermo-Calc)

A team of over 10 people at Thermo-Calc are dedicated full time to the development of CALPHAD databases. Database development essentially involves combining assessments of binary and ternary systems into large multicomponent databases. The currently available models and strategies for 3rd generation databases will be outlined, specifically the Einstein model, the two-state model for liquid and amorphous phase, a new magnetic model. Further, it will be shown how the same idea of lattice stability for the Gibbs energy can be extended to other material properties, such as mobilities, density, thermal and electrical conductivity, viscosity, surface tension, ... For all these, the syntax for entering the relevant parameters into a tdb file will be explained and demonstrated. 

Finally some new ideas will be presented on how CALPHAD assessments and database development can profit from machine learning ideas and methodologies. 

Part 2 - May 26, 2024, 3 - 4 pm: ADDITIVE MANUFACTURING (Nicholas Grundy, Thermo-Calc)

The reliability of finite element models (FEM) crucially depends on the reliability of the material properties used. It will be demonstrated how the data outlined in Part 1 is used as input for a FEM model of the Additive Manufacturing (AM) process. One of the outputs of FEM simulations are thermal gradients. It is these gradients, together with other material properties, that determine microstructure features such as columnar to equiaxed transition in the melt pool or precipitates and segregation profiles in the solid material. Examples will be shown how FEM simulations can be directly linked to kinetic simulations of nucleation and growth of precipitates and homogenization by diffusion. 

This section will include a live demonstration of Thermo-Calc`s additive manufacturing module including a subsequent connection of a calculated temperature vs. time profile with the Diffusion Module DICTRA and the Precipitation Module TC-PRISMA.

Part 3 - May 26, 2024, 4:15 - 5 pm: INDUSTRIAL APPLICATION (David Linder, QuesTek Europe)

This concluding section of the workshop will pull everything together and demonstrate examples of how CALPHAD data from part 1, and a collection of advanced modelling and simulation tools, including but not limited to FEM simulations of additive manufacturing from part 2, can be combined in a Integrated Computational Materials Engineering (ICME) framework to design and develop materials tailored for a specific production line and industrial application.

Reliability of assessments and databases is key for the CALPHAD community. In this workshop, software tools to ensure CALPHAD assessment quality are discussed. There will be three introductory talks:
First, Florian Tang shows how a user interface can support the assessor by providing valuable information about the CALPHAD optimization, using the FactSage Calphad Optimizer as example. Second, Moritz to Baben provides an example that shows how a data-centric approach can be used to detect probably wrong data. Finally, Bengt Hallstedt shares his experience as CALPHAD reviewer how he evaluates whether or not a CALPHAD assessment makes sense.
Together with the audience, it will be discussed what standard practices of CALPHADians should be made easy by software in order to ensure good CALPHAD assessment quality.

Agenda

2:00: User interface decisions in development of Calphad Optimizer (Florian Tang)
2:45: Data-based detection of unreasonable thermodynamic data (Moritz to Baben)
3:15: Human-based detection of unreasonable thermodynamic data (Bengt Hallstedt)
4:00: Discussion
5:00: End of the workshop

This additional pre-conference workshop will begin at 4 pm on Sunday, May 26, 2024.

Please click here for detailed information on the workshop.