“Modeling, microstructural characterization, mechanical and corrosion properties of the CrN/CrAlN multilayer coating produced by physical vapor deposition."

Abstract

In this research, CrN/CrAlN multilayer coating was deposited on X12CrNiMoV12-3 stainless steel samples and compressor blades by the physical vapor deposition (PVD) method. Based on the computational fluid dynamics model, an optimized thickness of less than 10 μm with a roughness of 0.35 μm was deposited. The coating's microstructure and phase composition were characterized by XRD and SEM. Nanoindentation, adhesion, scratch, and roughness tests as well as residual stress were realized in the coated samples. A Salt spray test was also done on the samples and blades to evaluate the corrosion resistance of the coating. The CrN/CrAlN coating's elastic modulus and hardness were 371 GPa and 1745 HV, respectively. The Corrosion resistance of coated samples and compressor blades was 930 and 50 h, respectively. The induced residual tensile stress of 176.23 MPa due to the required machining process of the compressor blade before the coating was the reason for the lower corrosion resistance of coated blades. to eliminate the residual stresses and improve the corrosion performance of the coating, the blades were subjected to the tumbling process before coating. By optimizing the tumbling process for 3 h, the residual tensile stress converted to a compressive stress of −129.11 MPa, and accordingly corrosion resistance of the coated blades increased to 950 h.