Thermo-Calc Used to Predict Phase Fractions when Partially Substituting Cobalt

Cobalt symbol on blue background with the words Thermo-Calc used to predict phase fractions when Partially Substituting Cobalt

A new publication in Acta Materialia investigates the possibility to partially substitute Cobalt with entropic alloys, focusing on the relative stabilities of the fcc and hcp structures.

Cobalt-base alloys are important for high temperature applications due to their possibility to form duplex fcc + hcp structures and their low stacking fault energy. However, there is an interest in substituting cobalt for economical, ethical and health reasons.

Both the thermodynamic and kinetic calculations in this publication were performed with Thermo-Calc software and the Diffusion module (DICTRA) together with the thermodynamic database TCHEA and the kinetic database MOBNI. Thermo-Calc was used to predict the phase fractions of fcc and hcp which were compared with experimental results. In the article, it is stated that the calculated thermodynamic values correlate relatively well with the experimental values. The authors concluded that designing duplex fcc + hcp Co-based alloys with computational tools is feasible.

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The article An experimental and theoretical study of duplex fcc + hcp cobalt based entropic alloys is written by Wei Wang, Ziyong Hou, Raquel Lizárraga, Ye Tian, R.Prasath Babu, Erik Holmström, Huahai Mao and Henrik Larsson. Both Huahai Mao and Henrik Larsson are Thermo-Calc Software employees. The article is available at Science Direct.

Abstract

Martensitically formed duplex fcc + hcp Co-based entropic alloys have been investigated both experimentally and theoretically. Theoretical predictions are in good agreement with experimental observations. A fair correlation is found between calculated driving forces for a partitionless fcc → hcp transformation and experimentally obtained phase fractions.

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