Corrosion Experiments of the Candidate Materials for Liquid Lithium Lead Blanket of Fusion Reactor

摘要

Liquid lithium lead (LiPb) eutectic is considered as one of the promising candidates of tritium breeder materials for fusion reactors. Series experiments on compatibility of LiPb with candidate structural materials such as CLAM steel and SiCf/SiC composites have been done in DRAGON serious experimental devices in FDS team such as DRAGON-RTand stirred pot device in NIFS at 500°C and 600°C, respectively. The weight loss of CLAM specimens exposed in flowing LiPb with the velocity of 0.17m/s increased with temperature, and the morphology and composition of the corroded surfaces were done by SEM observation and EDX analysis. The coating specimens including AI2O3 and FeAl/AkOs coatings prepared on the CLAM specimens were also exposed in the DRAGON-RT device, the results revealed that there was no obvious thinning observed on the outer surface of the protective coating. Preliminary analysis of SiCf/SiC composites specimens indicated that the mullite coating with plasma spray method on the SiCf/SiC composites specimen corroded in the high temperature LiPb, but no obvious corrosion attack was observed on the specimen surface, while the matrix and fiber of reaction-sintered composites showed slightly corrosion attack after exposure in static LiPb at 800°C for 200 hrs. Further corrosion experiment will be carried out in the near future.