The effect of proton irradiation on the corrosion resistance of Al2O3 in 550 °C liquid lead–bismuth eutectic

Abstract

Al2O3 is a promising candidate coating material for liquid lead-bismuth eutectic (LBE) corrosion resistance due to its excellent physical and chemical stability. However, Al2O3 material is also exposed to intense neutron irradiation in reactor and irradiation-induced defects may affect its corrosion resistance. In this study, Al2O3 single crystals were irradiated by H+ ions, and then were exposed to LBE at 550 °C for 2000 h. The effects of irradiation on their corrosion resistance were investigated. Although irradiation caused numerous of defects, such as point defects, defect clusters, and dislocation loops, they did not affect the corrosion resistance of the Al2O3 to LBE. The behaviors of doped H atoms within Al2O3 crystal are of great significance. They tended to aggregate and form blisters on the surface. This is the main factor that results in the failure of Al2O3 in LBE. Moreover, there is an abnormal relationship between the size of blister and H fluence. Low fluence was actually more likely to produce larger blisters than high fluence. The long-term high-temperature annealing effect during the corrosion process dominated the recombination of irradiation defects and the interaction between defects and H atoms. Our research contributes to the evaluation of Al2O3 material under irradiation and high-temperature LBE environments.

Keywords

• Single-crystal Al2O3
• H+ irradiation
• Defects
• LBE corrosion