Corrosion behavior and passive film characteristics of AlNbTiZrSix high-entropy alloys in simulated seawater environment

The corrosion and passive behavior of AlNbTiZrSix high-entropy alloys (HEAs) with different Si contents were investigated in simulated seawater environment at room temperature. The results showed that the average grain size decreased with an increase in Si content, which was associated with the inhibiting effect on grain growth due to the precipitation of Zr5Al3 phase. The passive film of the HEAs primarily consisted of TiO2, Nb2O5, and ZrO2. Preferential corrosion occurred in Zr5Al3 phase regions, and the addition of Si reduced passive film stability, worsening corrosion resistance.