Functional Coatings for the Receiver of Concentrated Solar Power Plants

The efficiency of concentrated solar power technology is based on the functionality of exterior and interior absorber tube surfaces. While a high solar absorptivity and thermocyclic oxidation resistance are targeted for the exterior surfaces, a high resistance against molten nitrate corrosion is essential for the functionality of the interior surfaces. In this study, a bi-layer coating concept combining a Cr-diffusion coating with a top-coat ensured a high thermocyclic oxidation resistance together with high absorptivity for the exterior surfaces. For the interior surfaces, the molten nitrate corrosion resistance of ferritic-martensitic steels was significantly increased via the application of diffusion aluminide coatings.