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Property Model Calculator

Predict and optimize properties of materials using models stored within the software, and optionally, your own models.

About the Property Model Calculator

The Property Model Calculator is a calculator within Thermo-Calc that offers predictive models for material properties based on their chemical composition and temperature. The Property Model Calculator is included with all Thermo-Calc installations, along with a general set of models for setting up some of the most common calculations, such as driving force, interfacial energy, liquidus and solidus temperature, and phase transition temperatures in general.

Users can buy additional packages of models or develop your own models using TC-Python, an SDK available for purchase with Thermo-Calc

A Quick and Easy Path to Calculate Properties

The Property Model Calculator offers users a quick and easy path to calculate any ordinary property available from a Thermo-Calc calculation, for example, amount of phase, phase constitution, transition temperature, or similar. Furthermore, the calculator allows users to calculate additional properties using models that take the ordinary properties as input, such as coarsening rate coefficients, martensite start temperature, and yield strength. In addition, users can write and implement your own models utilizing TC-Python, an SDK available for purchase with Thermo-Calc.

Support for Materials Design

The Property Model Calculator has been developed to facilitate the design of materials. Consequently, it is easy to study how different variables influence defined properties of interest (or design variables) and to cross-plot the result to identify optimums in, for example, composition. Additionally, the Property Model Calculator gives users the ability to perform uncertainty or sensitivity analyses, for instance, to study how variations in chemistry influence a specific property.

Property Models

Property Models are the engine that drive the Property Model Calculator. They simplify the process of setting up the calculations. They expand the functionality available in Thermo-Calc and make the software easier to use. Models can be used on their own or several can be evaluated simultaneously over a range of compositions to cross plot their results.

Models are Grouped within Libraries in the Software

The models are stored within libraries in the software, a library being a group of similar models. The software comes with a General Model Library, which includes models to help users to quickly set up some of the more common calculations using the Property Model Calculator. Users can also purchase libraries for specific materials or create custom models and develop your own libraries.

General Model Library

The General Model Library comes standard with all Thermo-Calc installations. It includes several models to help users quickly set up some of the more common calculations using the Property Model Calculator:

  • Coarsening Model - calculates the coarsening rate coefficient K (m3/s) of one or several spherical precipitate phases in a matrix phase.
  • Crack Susceptibility Coefficient - calculates the hot tearing tendency during solidification. It is particularly useful during the casting of, for example, aluminum and magnesium alloys.
  • Driving Force Model - calculates the thermodynamic driving force for a phase.
  • Equilibrium Model - calculates the equilibrium for the given conditions. Optionally define additional Function Definitions.
  • Equilibrium with Freeze-in Temperature* - calculates equilibrium at the freeze-in temperature and evaluates the properties at a different temperature. This model is particularly relevant for electrical and thermal properties*
  • Interfacial Energy Model - estimates the interfacial energy between a matrix phase and a precipitate phase using thermodynamic data from a CALPHAD database.
  • Liquidus and Solidus Model - this model offers a fast and easy way to complete this common calculation. For example, you can easily use uncertainty calculations, varying one or more conditions, and see how that affects the liquidus and solidus temperatures.
  • Phase Transition Model - calculates the point when a new phase may form by varying set conditions. The model is useful to determine melting temperature, boiling temperature, or solubility limits. It returns the phase transformation temperature, or composition, depending on the varied condition.
  • Spinodal - calculates the spinodal line, which is defined by the condition where the second derivative of Gibbs free energy is zero (d2G/dx2 = 0).
  • T-Zero Temperature - calculates the so-called T0 line, which is defined as the temperature where two phases of identical chemical composition have the same molar Gibbs free energy. This temperature is an important quantity in the field of diffusionless phase transformations, such as martensitic transformation, since it is the upper limit where diffusionless phase transformations can occur.
  • Yield Strength Model - considers four contributions to the overall yield stress of the material: intrinsic strength for the pure elements, grain boundary strength, solid solution strengthening, and precipitation strengthening.

*This model uses thermophysical properties that are only available in some of the databases. If you are interested in this model, be sure to mention this to your sales agent.

General Model Examples

Thermo-Calc includes several examples to help users get started using the Property Model Calculator. Each of the models includes at least one example calculation, and most of the examples use DEMO databases, so they can be run by all users, regardless of which databases you purchase. Most examples can also be run using the Free Educational Package of Thermo-Calc.

Some of the examples also have accompanying videos that walk you step-by-step through setting up the calculation in the Property Model Calculator and include interpretation of the results. 

Videos about the Property Model Calculator

Steel Model Library

The Steel Model Library includes seven models that are developed specifically for those who work with steels. The Library is available for free to all users who have, or upgrade to, the thermodynamic and properties steel database TCFE version 9 or newer and the mobility steel databases MOBFE version 4 or newer, plus have a valid Maintenance and Support Subscription. The Steel Model Library includes the following models:

  • Martensite Temperatures Model
  • Martensite Fractions Model
  • Critical Transformation Temperatures Model (Liq, Sol, A1, A3, Acem, and so on)
  • Pearlite Model
  • Bainite Model
  • CCT Diagram Model
  • TTT Diagram Model

Develop Your Own Models 

Users can develop their own models and seamlessly integrate them into Thermo-Calc using the TC-Python Property Model Framework, available in TC-Python, an SDK available for purchase with Thermo-Calc. In other words, you can customize the software to meet your modeling needs.

Models are developed using the easy-to-learn programming language Python™, and model development is assisted with advanced features such as debugging of the Property Models and autocompletion. 

Property Models developed in the TC-Python Property Model Framework automatically populate in Thermo-Calc, where they can be configured and run in the Graphical User Interface, giving users access to all of the powerful features and calculation types* available in Thermo-Calc.

Additionally, because this program uses the Python language, users can use any python library, such as numpy, scipy, or scikit-learn, within the Property Models, making model development quite powerful.

Models are automatically encrypted, for safe and secure file sharing. 

TC-Python requires a license in addition to a standard Thermo-Calc license. 

Property Model Framework in TC-Python

Legacy Property Model Framework Guide

*Some calculation types, such as diffusion and precipitation simulations, require additional licenses for the relevant Add-on Modules

Calculation Types Included in the Property Model Calculator

The Property Model Calculator includes the following calculation types:

  • Single - calculates a single point
  • One Axis - varies a quantity on the X-axis
  • Grid- evaluates two axis variables of the selected quantities in the specified range and number of steps.
  • Min/Max - evaluates the property model(s) for all variations of the selected quantities at the given limits. The Mean field is as defined under Condition Definitions for the respective quantity. The total minimum and maximum of the model(s) results are shown in the Event log.
  • Uncertainty Calculation - evaluates the Property Model(s) where the values of the quantities are sampled from Gaussian distributions. The Mean field is as defined under Condition Definitions for the respective quantity. The result is visualized as a histogram or normal probability plot by adding a Plot Render activity.
  • Batch Calculation - allows for high throughput calculations by allowing users to upload a spreadsheet or text file into the calculator. Results can be compared to experimental values, if included in the uploaded file, using cross plots (i.e parity plots) or statistical plots.


The Property Model Calculator is included for free with all Thermo-Calc installations. It comes with one set of general models. Additional, material-specific models can be purchased, and users who have a license for TC-Python can develop your own models using the TC-Python Property Model Framework. If you do not already have a license for Thermo-Calc or you are interested in expanding your license, please contact us to discuss which license is right for you.

Learn More about the Property Model Calculator

A collection of videos demonstrating the capabilities of the Property Model Calculator.

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Hardenability Design of Steel

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