[T19] High Entropy Alloys

[14D-T19-08] Corrosion Behaviour of AlFeCrCoNi and FeCrMoAlTiNi High Entropy Alloys in Molten Solar Salts

*P. Alvaredo¹, R. Carbajales¹, C. Sobrino¹ (1.Universidad Carlos III de Madrid, Spain)

Keywords:Molten solar salta, electrochemical impedance spectroscopy (EIS), Extreme enviroments, Corrosion resistance, Molten Solar Salts

High entropy alloys are promising for applications involving extreme environmental exposure because of their excellent stability, which they maintain at high temperatures. This work studies the corrosion resistance of AlFeCrCoNi and FeCrMoAlTiNi in molten solar salts and compares it with a reference stainless steel currently used in thermosolar plants. PM processing has been adopted in order to better understand how changes in the microstructure affect the behavior of alloys and to enable more control over the microstructural properties through the use of a fast sintering technology, Spark Plasma Sintering (SPS). Two combinations of solar salts have been used to monitor the corrosion behavior in molten salts using polarization and electrochemical impedance spectroscopy (EIS). The traditional one, a nitride mixture, and a second solar salt made of a chloride mixture proposed because of its higher heat capacity and lower price. The results indicate a promising use of HEA in applications in extreme and corrosive environments.