Influence of coatings obtained by PVD on the properties of aircraft compressor blades

Abstract

In this paper, the results of investigations to increase aircraft compressor blade durability were presented. The blades were made of the martensitic steels. The coatings were obtained by the physical vapour deposition (PVD) method. TiN and (Ti, Al)N coatings on a titanium nitride base and CrN and CrCrN multilayer coatings on a chromium nitride base were used in the tests. Low corrosion resistance of the TiN coatings was shown in laboratory tests. The (Ti,Al)N coatings, particularly CrN and CrN modifications, behaved better. Coating density and chemical interaction of the coating and steel in the corrosive medium were shown to have an influence on the blade properties. A significant increase in the corrosion resistance was achieved by using the diffusion and chemical treatment of coatings obtained by the PVD method. Investigations of coatings in a humid atmosphere containing SO 2 showed very low resistance of the steel. The resistance of the coatings was increased significantly by additional chemical treatment.