Deuterium permeation and thermal behaviors of amorphous silicon carbide coatings on steels

In this study, deuterium permeation measurements for SS316 and F82H steels coated with amorphous silicon carbide films by radio frequency magnetron sputtering are performed. The driving deuterium pressure dependence of the coated sample shows a large surface contribution. Deuterium trapping in the amorphous structure is suggested by the temporal change in the permeation flux. Permeation reduction factors of 103 are achieved with 1.5-μm-thick coated F82H at 723–823 K; however, the coating degraded at 873 K. Cracks are generated in the coating because of the tensile stress derived from a large difference in the thermal expansion between the coating and the steel.