Enhancing oxidation resistance with Si in Fe₃₆Ni₃₆Al₁₅Cr₁₀Si₂Mo₁ multi-principal element alloy at 700 °C

The eutectic high entropy alloys with large amounts of Al and Cr have exhibited superior oxidation resistance. Here, we confirmed that Si could further enhance the oxidation resistance by forming a continuous oxidation layer in Fe₃₆Ni₃₆Al₁₅Cr₁₀Si₂Mo₁ alloy. Si promoted the outward diffusion and transformation of Al which effectively enhanced the oxidation resistance. The FeCr₂O₄ spinel and silicate formed by the solid-state reaction also contributed to the oxidation resistance. The thermodynamic and kinetic factors were then discussed to understand the inherent oxidation mechanism of the dual-phase Fe₃₆Ni₃₆Al₁₅Cr₁₀Si₂Mo₁ alloy, which provide new insights into the dual-phase alloy design and oxidation resistance.