The thermal conductivity of high entropy alloys does not follow typical trends in metals. Not only are they an order of magnitude less conductive than what rule of mixtures would predict, but their conductivities are also known to increase with temperature between 300-550K. Here, transport is calculated in an analytical model as the sum of contributions from the electron and phonon subsystems. For the lattice subsystem, conductivity is treated with the Leibfried and Schlömann formulation with perturbations for both electron-phonon interactions and point defect scattering. The electron subsystem is dominated by alloy scattering, which is calculated based on a virtual crystal approximation derived from each constituent’s Lennard-Jones potential. The model predictions are then compared to time domain thermoreflectance measurements in the Al0.5CoCrFeNiCu as well as previously published measurements of the Al0.37CoCrFeNi alloy.
This work was supported by the Sandia National Laboratory Directed Research and Development
(LDRD) program. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under Contract No. DE-NA0003525. This work describes objective technical results and analysis. Any subjective views or opinions that might be expressed in the paper do not necessarily represent the views of the U.S.
Department of Energy or the U.S. Government.