A novel low-temperature approach for fabricating α-Al2O3-based ceramic coating as tritium permeation barrier

α-Al 2 O 3 -based coatings have attracted great interest as promising tritium permeation barrier used in the D-T fusion reactor system. However, it is still difficult to fabricate α-Al 2 O 3 coatings at a low temperature that can be endured by the steel substrate. Herein, thermal-chemical reaction method was developed for the fabrication of α-Al 2 O 3 -based coatings. α-Al 2 O 3 /AlPO 4 composite coating was successfully formed on the steel substrate at 500   °C. The resulted coating was uniform and compact without presence of pores and cracks. The binding strength of the coating was tested and the result indicated its good adherence to the substrate. Moreover, the coating thickness could be easily controlled. The low-temperature approach developed is expected to provide a new platform for fabricating α-Al 2 O 3 -based coatings as tritium permeation barrier. This approach is also applicable to the fabrication of other ceramic coatings.