In-situ reaction-generation self-healing superior antioxidation layer induced by Al-Y sol-gel film on the AISI304 steel

In this study, an Al-Y sol-gel film is prepared on the AISI304 steel and its effect on the high temperature oxidation resistance is evaluated by the cycle oxidation at 900 ℃ in the air. The resulting intact oxide layer, composed of (Al, Cr)₂O₃ and MnCr₂O₄ phases, effectively slowing down the oxidation rates at 900 ℃. The general cracks in the sol-gel film during the oxidation process are found to be self-healed by a growing spinel MnCr₂O₄ phase from the substrate, attributed to its low Gibbs free energy and the sufficient Cr source from the adjacent substrate. Furthermore, the oxide layer originates from the interaction between sol-gel film and the substrate which enhances the binding between the oxide layer and the substrate. Thus, it could be confirmed that a self-healing superior antioxidation layer is generated on the surface of AISI304 steel through an in-situ reaction induced by the Al-Y sol-gel film during high-temperature oxidation procedure.