Promoted Mechanical Properties and LBE Corrosion Resistance of FeCrAlTi-ODS Coatings Deposited by Magnetron Sputtering

A key issue with lead-cooled fast reactors is the corrosion vulnerability of fuel cladding and core components, which will endanger the structural materials’ integrity and the operational safety of the reactor system. The FeCrAlTi-ODS (Oxide Dispersion Strengthened) alloy coatings are prepared by the Magnetron Sputtering technique under different bias voltages to shield structural elements in lead-cooled fast reactors from corrosion caused by lead-bismuth eutectic (LBE). A comprehensive study examines their mechanical attributes and resistance to LBE-induced corrosion. Compared to the bare substrate of austenitic 316L steel, the FeCrAlTi-ODS alloy coatings exhibit significantly improved binding force and hardness. The hardness (H) reaches 11.52 GPa (twice that of the bare substrate), and the elastic modulus (E) reaches 172.89 GPa. After the corrosion of bare substrate 316L steel by LBE, the oxygen element penetrated was obvious, and the Nickel element underwent selective migration. The FeCrAlTi-ODS alloy coatings show promising LBE corrosion resistance, and the FeCrAlTi-ODS alloy coating prepared under different bias can effectively protect the substrate material, which is attributed to the formation of protective FeCr2O4 film on the surface. The compact oxide film significantly prevents the further infiltration of the oxygen element and the migration of metal elements.