Enhancing the oxidation behaviors of Zr alloys for nuclear fuel cladding using nanolamellar Cr/CrN coating

Cr, CrN, and nanolamellar Cr/CrN coatings were deposited on Zr-4 substrate by multi-arc ion plating in Ar, N2, and Ar + N2, respectively. The oxidation behaviors of these various types of Cr-based coatings in steam under different temperature-time conditions were compared. The nanolamellar Cr/CrN coating had a smaller weight gain, a smoother oxide surface, fewer pores, no cracks, and could block the interdiffusion between Cr-Zr by generating a ZrN layer. The designed nanolamellar Cr/CrN coating can effectively combine the advantages of Cr and CrN coatings to show better resistance to oxidation. Oxidation mechanisms have also been discussed in detail.