Department of Materials Science & Metallurgy: Research paper of the month

Department of Materials Science & Metallurgy

Research paper of the month

August 2015 - Modelling solid solution hardening in high entropy alloys

High entropy alloys (HEAs) are multicomponent systems composed of elements displaying a nearly equiatomic configuration with contents ranging from 5 to 35 at.%. The high entropy of such mix benefits the formation of face-centred cubic (fcc) or body-centred cubic (bcc) solid solutions. They display an excellent mechanical response and good wear resistance at low and high temperatures, as well as good plastic behaviour. It is generally accepted that solid solution hardening (SSH) is the main origin for the exceptional mechanical properties of HEAs. A model for predicting SSH in HEAs is proposed in this paper. This is the extension of Labushs classical approach for binary systems, to multicomponent alloys. The results collected from the literature on HEAs show good agreement with the predicted effect of SSH in yield strength computed by the model. New compositions can be proposed by using this method to enhance the mechanical response of HEAs.

Figure: Comparison of experimental and computed yield strengths for high entropy alloys reported in the literature.

I. Toda-Caraballo and P.E.J. Rivera-Diaz-del-Castillo, "Modelling solid solution hardening in high entropy alloys", Acta Materialia 85 (2015) 1423

doi: 10.1016/j.actamat.2014.11.014