HYDROGEN BARRIER COATINGS AND THEIR PERMEATION RESISTANCE

This review discusses the state of the art in hydrogen permeation for a variety of coatings. Hydrogen ingress into structural materials can be detrimental due to corrosion and embrittlement. To enable safe operation in applications requiring protection from hydrogen isotopes, recent advances in material design and performance characterization of barrier coatings to prevent hydrogen isotope absorption ingress and permeation are summarized. Alternative coating concepts can provide greater resistance to hydrogen isotope permeation along with other improved properties such as mechanical strength and thermal resistance. The information presented here focuses on recent findings of promising hydrogen barriers including oxides, nitrides, carbon, carbide, MAX phases, and metals and their mechanical strength, hydrogen uptake, and radiation resistance.