Estimation of diffusional effects on solution hardening at high temperatures in single phase compositionally complex body centered cubic alloys

Abstract

Solution hardening in body centered cubic alloys as a function of temperature can be well described by the Suzuki model. This model includes significant strengthening from the dragging of edge dislocation dipoles produced by kink collisions along the screw dislocations. However, the model does not consider diffusion-controlled processes. Here we estimate a critical temperature Tcr above which diffusional effects become important, resulting in the collapse of edge dipoles. Loss of edge dipoles leads to a significant decrease in yield strength above Tcr and marks the temperature limit for structural applications of these single phase body centered cubic alloys.