Structural and Phase Characteristics and Properties of Multilayer Cr/CrN Coatings Obtained by Magnetron Sputtering

Multilayer Cr/CrN coatings with two-, four-, and six-layer architectures were deposited on E110 zirconium alloy substrates by reactive magnetron sputtering. The effect of layer number on structure, phase composition, and performance was systematically investigated. XRD revealed that the coatings consisted mainly of CrN and Cr phases, with an increase in the CrN fraction and texture intensity as the number of layers increased. Cross-sectional SEM and EDS analyses confirmed the formation of dense multilayer structures with clear Cr/CrN interfaces and strong adhesion to the substrate. Nanoindentation showed a progressive increase in hardness and Young’s modulus from 2.59 ± 0.09 GPa and 97 ± 2 GPa (two-layer) to 5.0 ± 0.27 GPa and 110 ± 4 GPa (six-layer), respectively. Tribological and scratch tests demonstrated that the 6-layer coating exhibited the lowest wear rate and highest adhesion strength (Lc ≈ 20.5 N).