Corrosion resistance of spray-formed A0,75CrFeCoNi high entropy alloy

Abstract

Materials used in extreme condition environments such as those found in petrochemical and naval industry must present high mechanical and corrosion resistance. High Entropy Alloys (HEA) of AlCrFeCoNi system combine high mechanical resistance and toughness. These alloys contain Cr, alloying element usually associated with high corrosion resistance in aggressive environments containing chlorides. Although there are articles reporting the corrosion resistance of HEAs, none of these evaluated the corrosion resistance produced by spray forming, processing route near closer to the industrial reality. The purpose of this research project is to produce the Al0,75CrFeCoNi HEA composition by spray forming, characterize its microstructure and correlate it with its corrosion resistance in chloride-containing electrolytes. X-ray diffraction and scanning electron microscopy will be carried out for microstructural characterization. Non-destructive (linear polarization resistance) and destructive (potentiodinamics polarization) electrochemical tests will be carried out in solutions with different chlorides contents in order to analyze the formation and stability of a passive film. The morphology and severity of pitting attack will be evaluated by microscopic analysis of the corroded surface. At the end of the project, it is expected to identify whether the spray-formed Al0,75CrFeCoNi, which has high mechanical strength, also presents a high corrosion resistance for applications in aggressive chlorides-containing environments.