For questions concerning CALPHAD (CALculation of PHAse Diagrams), a methodology introduced in the 1960s by Larry Kaufman.

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### Persistent errors in single equilibrium calculations (Thermo-Calc)

When running single point equilibrium calculations on an array of compositions I come across some compositions (for specific examples see below) that return the error ...
• 602
661 views

### How to create pseudo-binary phase diagrams using Thermo-Calc GUI?

How do you create pseudo-binary phase diagrams using Thermo-Calc? For instance how would I recreate the pseudo-binary phase diagrams shown below. I would prefer a method of doing this in the GUI (...
• 602
194 views

### How to calculate phase regions using CALPHAD for higher order systems (>3 elements)?

I primarily use Thermo-Calc so I will use that to describe my problem but I am interested to hear general CALPHAD insight as well. Using Thermo-Calc I can quickly get an idea of the phase regions ...
• 602
449 views

### Thermo-Calc: how to suspend specific composition sets?

I am attempting to calculate the driving force of nucleation for several different precipitate phases using TC-Python. To this I want to suspend all phases, except for the matrix phase (e.g. FCC_L12). ...
• 602
267 views

### Pycalphad most efficient way to gather equilibirum phase data for set of alloy compositions?

What's the most efficient way to get the equilibrium phases and phase fractions for a set of alloy compositions? For context, I'm coming from Thermo-Calc/TC-Python where I would just loop through the ...
• 602
252 views

### Pycalphad "Failed while parsing" Yttrium from light alloys database

The code in question is just 2 lines used to import the "COST507 database for light alloys" (downloaded from the opencalphad homepage http://www.opencalphad.com/). ...
• 602
122 views

### Is it possible to analytically solve for a particular phase region of a CALPHAD database? (instead of guessing and checking)

As I understand it, a given CALPHAD database is essentially just a set of equations that model the Gibbs free energy of each phase within a given alloy system (set of elements). Typically, the main ...
• 602
390 views

### Thermo-calc: Calculate precipitation driving force by parallel tangent construction

I want to calculate the difference in Gibbs free energies between a Zr-Cu-Al liquid (composition - Zr 65 Cu 27.5 Al 7.5 at%) and the CuZr2 solid phase as a function of temperature (300 - 1000 K). In ...
192 views

### What information about a crystalline solid material goes into calculating phase diagrams in Thermo-Calc, and how?

Gibbs free energy, $G$, for a crystalline solid material could be described as: $$G\: =\: H_{T=0}\: +\: H_{T>0}\: +\: \text{ZPE}\: -\: T\cdot S,$$ Where $H$ is enthalpy, ...
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410 views

### How to get order constitution data for single equilibrium calculation in Thermo-Calc's TC Python module?

I know that it is possible to get order constitution data for phases when using Thermo-Calc's GUI (e.g. to get "BCC_B2 DISORD" instead of just "BCC_B2") for a single equilibrium ...
• 602
276 views

### Why does Thermo-Calc one axis equilibrium calculation get stuck in never ending loop? [closed]

I've been trying to run a Thermo-Calc one axis equilibrium calculation on some quaternary alloys in the TCHEA4 database. Most of the calculations work fine, but for some alloys it gets stuck in a loop ...
• 602
432 views

### For a Thermo-Calc database, is it possible to view the equation/parameters of the Gibbs free energy models?

I want to get the equations that model free energy for a given phase in a given alloy system (see attached image). I do not just want to get values of free energy for specific compositions. Is it ...
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