Solid particle erosion resistance of Cr-base gradient multilayer coatings

Abstract The phase constituents and mechanical properties of Cr/CrAlN and Cr/CrN/Cr/CrAlN coatings which prepared by Arc Ion Plating were investigated in this work. The stress variation of the coating process was investigated by the finite element method and the failure mechanism of the coatings was analyzed. The results suggested that the, Cr/CrN/Cr/CrAlN coating have fewer surface micro-particles, higher adhesion strength (86.7 ± 2.1 N), and lower residual stress (−1.665 ± 0.042 GPa) compared with Cr/CrAlN coating. In addition, the erosion resistance performance of the multilayer coatings is obviously higher than that of the uncoated specimen. According to crack growth and stress analysis, it is found that Cr/CrN/Cr/CrAlN coating has better longitudinal and transverse stress dissipation ability. During the impact of solid particles, high tensile stress is the main reason for the formation and propagation of brittle cracks in the coating. In addition, according to the plastic-brittle (DBT) transition of the Cr layer, it is inferred that the fracture failure mechanism of the coating is a joint mechanism of brittleness and toughness.