Advanced Al2O3 coatings for high temperature operation of steels in heavy liquid metals: a preliminary study

In this work, we propose a nanocrystalline Al2O3/amorphous Al2O3 composite coating for protecting steels operating in heavy liquid metals (HLMs) at high temperature. The coating is grown by Pulsed Laser Deposition (PLD). Previous work by García Ferré et al. [27] has shown that PLD-grown Al2O3 attains an unusual ensemble of metal-like mechanical properties and strong interfacial bonding, all combined with the chemical stability and resistance to wear of ceramics. In a short term corrosion test (500 h), 9Cr1Mo steel samples were coated and exposed to stagnant lead at 550 °C. Cross-sectional SEM and EDX analysis revealed no signs of corrosion.