Aluminizing of metallic materials for fusion power applications

The necessity of coatings is fundamental for both liquid metal blanket concepts. In a water-cooled liquid metal blanket concept, the coating has to behave as tritium permeation barrier to minimize the tritium loss into the cooling water. An electrical insulation against the liquid metal is required in a self-cooled liquid metal blanket to reduce the MHD pressure drop. Therefore, V and V-base alloys and as well the ferritic steel MANET were coated by means of hot-dip aluminizing. The different base materials are dipped under inert atmosphere into molten Al to form aluminide layers on the surface. The nitriding of the aluminide layers on V and V-base alloys was tried in a sodium solution containing 0.15 wt% Li under N2 atmosphere. The aluminide layers on the MANET steel were oxidized at high temperature in air. The results of the hot-dip aluminizing and the following nitriding reps. oxidation will be presented in this paper. (author)