OpenCalphad - a free thermodynamic software

Abstract

Thermodynamic data are essential for the understanding, developing, and processing of materials. The CALPHAD (Calculation of Phase Diagrams) technique has made it possible to calculate properties of multicomponent systems using databases of thermodynamic descriptions with models that were assessed from experimental data. A large variety of data, such as phase diagram and solubility data, including consistent thermodynamic values of chemical potentials, enthalpies, entropies, thermal expansions, heats of transformations, and heat capacities, can be obtained from these databases. CALPHAD calculations can be carried out as stand-alone calculations or can be carried out coupled with simulation codes using the result from these calculations as input. A number of CALPHAD software are available for the calculation of properties of multicomponent systems, and the majority are commercial products. The OpenCalphad (OC) software, discussed here, has a simple programming interface to facilitate such integration in application software. This is important for coupling validated thermodynamic as well as kinetic data in such simulations for obtaining realistic results. At present, no other high quality open source software is available for calculations of multicomponent systems using CALPHAD-type models, and it is the goal of the OC source code to fill this gap. The OC software is distributed under a GNU license. The availability of the source code can greatly benefit scientists in academia as well as in industry in the development of new models and assessment of model parameters from both experimental data and data from first principles calculations.

The OpenCalphad thermodynamic software interface

“…The background for the development of a free thermodynamic software for multicomponent calculations using the CALPHAD method (CALculation of PHAse Diagrams) is described by Sundman et al [1]. A very limited first version of the OpenCalphad (OC) software was released in 2013.…”

The Calphad Method and Its Role in Material and Process Development

“…In recent years the development of free CALPHAD software, such as Gibbs [77], OpenCalphad [78] and pycalphad [79], has gained momentum. These programs have all of the main features that can be expected from CALPHAD software with the exception that Gibbs is limited to calculations of systems with simple regular-solution and stoichiometric models.…”

The implementation of an algorithm to calculate thermodynamic equilibria for multi-component systems with non-ideal phases in a free software

“…The implementation is done as part of the Open Calphad (OC) initiative [10] to provide a free software for thermodynamic calculations. This open source software has a GNU license and is available on the web [11,12] and the intention is to integrate it in several different software for example to use results from firstprinciples calculations [13][14][15], in assessments for databases [16] as well as for simulations of phase transformations and microstructures including kinetic data [17,18] and in industrial applications [19][20][21].…”