Study on the Process Parameters and Corrosion Resistance of FeCoNiCrAl High Entropy Alloy Coating Prepared by Atmospheric Plasma Spraying

FeCoNiCrAl high-entropy alloy (HEA) coating was prepared by air plasma spraying, and the coating’s morphology and properties under different power parameters were analyzed. The results show that the spraying power significantly affects the morphology of the coating during plasma spraying. The molten droplets formed during the preparation process of HEA coatings tend to combine with oxygen, with aluminum bonding particularly strongly with oxygen, resulting in the presence of aluminum oxide within the coating, while other elements exhibit weaker bonding with oxygen. The optimal spraying power is 12 kW, and coatings prepared at this optimal power exhibit advantages such as low porosity, uniform element distribution, and excellent corrosion resistance. The aluminum in the HEA coating forms a relatively stable compound with oxygen, creating a Cr-depleted and Al-enriched region. This region is less prone to passivation during corrosion and more susceptible to reacting with corrosive media, leading to localized corrosion of the coating.