Effect of Mechanical Damage on Tritium Permeability Resistance of FeAl/Al2O3 Coating on 316L Stainless Steel

Depositing a tritium permeation barrier on the surface of materials is a key method for reducing tritium permeability. During actual operational processes, the surface of the tritium permeation barrier may experience mechanical damage, such as spalling and scratches. The hydrogen permeability resistance of the coating will degrade due to such forms of mechanical damage. It is a significant engineering challenge to evaluate the impact of these damages on the coating's tritium resistance. In this experiment, the mechanical damage to the FeAl/Al₂O₃ tritium permeation barrier on 316L stainless steel was simulated through scratching, debonding, and thermal shock. Subsequently, a hydrogen isotope gas drive permeation (GDP) test was conducted. The influence of the degree of mechanical damage on the coating's tritium permeation behavior was assessed and discussed. The results indicate that, under the same damage mechanism, the coating's tritium permeability resistance is positively correlated with the integrity of the coating. Additionally, the impact of scratches on the coating surface is more severe than that of other damage mechanisms.