Effect of LBE corrosion on microstructure of amorphous Al2O3 coating by magnetron sputtering

The amorphous Al2O3 coating with a thickness of approximately 3.3 mu m was prepared on ferritic/martensitic steel to investigate the corrosion resistance in contact with static liquid lead-bismuth eutectic from 100 h to 1000 h at 550 degrees C. The results showed that Al2O3 coating had poor wettability and could effectively protect the substrate from liquid lead-bismuth eutectic corrosion. However, the structure of the coating changed from an amorphous phase to a dual-phase structure during the corrosion process, leading to the formation of voids. The microscopic corrosion mechanism of Al2O3 coating was also elucidated in detail.