Nanostructuring for Enhanced Thermal Conductivity at High Temperatures in an Inconel 600 Alloy

We report here on the results of first principles calculations on the thermal and mechanical properties of an Inconel 600 like alloy of the composition Ni\(_{18}\)Cr\(_{4}\)Fe\(_{2}\). Alloys of this type have important high temperature applications and of interest are their mechanical and thermal properties within a temperature range of 500 K to 1000 K. A specific concern of this study was the thermal conductivity. We sought out what atomic level arrangements might lead to enhancements in the thermal conductivity of this material. Our results suggest that the thermal conductivity for this alloy can be enhanced by the presence of three-atom wide Ni nano-layers. Thermal conductivity values for this configuration, and 19 others, are predicted and the method for arriving at these estimates is described. Calculations of elastic moduli for the configuration of highest thermal conductivity were made. These results predict that this alloy will possess sufficient mechanical stability for use in high temperature applications, such as in liquid salt heat exchangers, where improvements in the thermal conductivity of the alloy are essential.