An advance process of aluminum rich coating as tritium permeation barrier on 321 steel workpiece

Mechanical and tribological properties of crystalline aluminum nitride coatings deposited on stainless steel by magnetron sputtering

“…Zhang et al [14] from China reported the formation of γ-Al 2 O 3 / (Fe, Cr, Ni) x Al double layered structure on 321 stainless steel and demonstrated their potential application as tritium permeation barrier coating. They electrodeposited 20 µm thick aluminium coating on 321 stainless steel tubes using ionic liquid bath and subjected them to heat treatment for aluminide formation followed it by selective oxidation for getting γ-Al 2 O 3 top layer.…”

Preparation technique and alloying effect of aluminide coatings as tritium permeation barriers: A review

“…Therefore, a technical approach of "ECX followed by selective oxidation" was proposed almost at the same time by FZK and CAEP [30,42]. With this technique, Zhang et al [31,42] prepared FeAl/Al 2 O 3 TPB coatings of high quality on stainless steel samples and containers. The deuterium PRF of the aluminide coatings in the air was 3000 at 500 C,~100 at 740 C, and the number of thermal cycling (room temperature~750 C) exceeded 20 times when prepared on a 321 workpiece (F80 Â 2 mm, 150 mm long) [31].…”

“…With this technique, Zhang et al [31,42] prepared FeAl/Al 2 O 3 TPB coatings of high quality on stainless steel samples and containers. The deuterium PRF of the aluminide coatings in the air was 3000 at 500 C,~100 at 740 C, and the number of thermal cycling (room temperature~750 C) exceeded 20 times when prepared on a 321 workpiece (F80 Â 2 mm, 150 mm long) [31]. Therefore, the ECX technique is very promising for the engineering preparation of aluminide TPB coatings in future fusion reactors.…”

“…The common adopted solution method is to form a functional gradient transition layer between the substrate and the coating. Generally, the technique of thermal treatment followed by high temperature oxidation is employed to form aluminide coatings typically FeAl/Al 2 O 3 after Al deposition on stainless steels [30,31]. At present, the aluminide coating has been selected as one of the prior developed TPBs for the TBMs by Europe, China, United States and India for its high permeation reduction factor (PRF), low thermal mismatch, metallurgical bonding, excellent compatibility, and selfhealing [35e37].…”

“…The preparation of aluminide TPB commonly involves two steps of aluminization and oxidation [30,31]. Aluminization is to form a transition layer of (Fe, Al) solid solution or FeeAl metallic compounds on the substrate surface via interdiffusion between Al atoms from a certain Al source and Fe atoms form the steel substrate.…”