Study of an iron-aluminide and alumina tritium barrier coating

An iron-aluminide and alumina tritium barrier coatings prepared by the high-activity pack-aluminizing and controllable pre-oxidizing processes have been investigated in this paper. A uniform iron-aluminide layer with Al content about 30 wt% and thickness between 15 and 25 μm was formed on the 316L samples at a temperature lower than 1043 K. A surface alumina film with thickness about 200–500 nm was selectively formed by pre-oxidizing the iron-aluminide layer. The 316L tube coated and oxidized only one side with the inner surface of Fe–Al and alumina composite coating achieved a Tritium Permeation Reduction Factor (TPRF) more than 3000 in the gas phase tritium permeation test.