Material compatibility with isothermal Pb–Li

Abstract

Eutectic Pb –Li is a leading candidate for current fusion blanket concepts as a coolant. However, there is very little data about the compatibility of most materials with Pb–Li above 500°C where the dissolution rate of many conventional alloys increases rapidly. Current work is beginning to assess Pb–Li compatibility from 500 to 800°C using isothermal capsule experiments. Aluminide coatings hold some promise in protecting conventional Fe-base alloys at 600 – 700°C. However, there is a significant initial Al loss that has not been clearly explained. Furthermore, the reaction product with coated materials is LiAlO₂ rather than Al₂O₃ at 600° and 700°C. Even when pre-oxidized to form α-Al₂O₃, an alumina layer on FeCrAl transformed to LiAlO2 at 700° and 800°C. At 500°C, the preformed oxide partially transformed from alumina and some Li was detected in the oxide layer.

Keywords:

• Pb–Li compatibility
• aluminide coating