Compatibility of erbium oxide coating with liquid lithium–lead alloy and corrosion protection effect of iron layer

Abstract Li–Pb compatibility of Er 2 O 3 and Er 2 O 3 -Fe two-layer coatings has been explored for an understanding of corrosion behaviors and effects of the protection layer. The coatings were peeled off after static Li–Pb immersion test at 600 °C due to the degradation of adhesion between the coating–substrate interface. A loss of Er and then subsequent corrosion of Er 2 O 3 were shown after immersion at 500 °C for 500 and 1505 h. However, the outer Fe layer played a role to decrease corrosion rate of the coatings by comparing with the results of Er 2 O 3 single layer coatings. Deuterium permeation measurements after corrosion tests at 500 °C showed that the Er 2 O 3 coatings kept permeation reduction factors of 10 2 –10 3 after 500 h immersion, but seriously degraded after 1505 h immersion. Corrosion mechanisms suggest that corrosion protection properties will be modified by an optimization of the outer Fe layer and a control of oxygen concentration in Li–Pb.