Deuterium permeation properties of Y2O3/Cr2O3 composite coating prepared by MOCVD on 316L stainless steel

• Y2O3/Cr2O3 composite coating exhibited better deuterium inhibition performance than Y2O3 coating.
• Y2O3/Cr2O3 coating exhibited a stable permeation flux at high temperature.
• Cr2O3 layer contributed to the completely decomposition of original precursor.
• The prepared Y2O3/Cr2O3 composited coating possessed a stoichiometric atomic ratio.

The effect of Cr2O3 layer on the deuterium permeation properties of Y2O3/Cr2O3 composite coating was investigated. Composite coating was prepared on 316L stainless steel by metal organic chemical vapor deposition (MOCVD). The Cr2O3 layer contributed to the completely decomposition of the original precursor with no presence of unreacted or partially reacted precursor molecules. The deuterium permeation inhibition performance of the coatings was examined by deuterium permeation measurement. The Y2O3/Cr2O3 composite coating exhibited better deuterium inhibition performance than the single-layer Y2O3 coating with the same thickness. The permeation reduction factor (PRF) value of the Y2O3/Cr2O3 composite coating was 167–477 at temperatures of 823–973 K, while the PRF value of the single-layer Y2O3 coating was 96–292 at 823–973 K. Moreover, the Y2O3/Cr2O3 composite coating exhibited a stable permeation flux, while a spike of the permeation flux was observed for the single-layer Y2O3 coating. Therefore, the Cr2O3 layer could enhance deuterium permeation inhibition properties significantly.