Rapid assessment of solid solution hardening via atomic size misfit parameter in refractory concentrated alloys

Abstract

Solid solution hardening (SSH) is one of the simplest methods to increase the strength of alloys, as only the concentration of the solute matters. It has been recently proposed that SSH in some concentrated body-centered cubic (BCC) alloys may be dominated by edge dislocation, unlike previously proposed SSH theories for dilute BCC alloys. In this study, we examine the dominant SSH mechanism in 14 binary refractory concentrated alloy (RCA) systems, by measuring the atomic size misfit and the modulus misfit parameters and applying them to the Labusch and Suzuki SSH-based models. Interestingly, we find a general trend that increasing the portion of the atomic size misfit parameter provides a better estimation of the measured SSH, which is a noticeable feature of the edge dislocation mediated SSH. While screw dislocation is expected to contribute to SSH in some RCAs with small atomic size misfits, this study offers a useful guideline on how to manipulate SSH of RCAs having large atomic size misfits.