Structure and Properties of Slurry Coatings on Gas Turbine Blades

Abstract—The slurry coatings fabricated by aluminizing and aluminosiliconizing using a binder consisting of colorless nitrolacquer and a solvent are studied. The replacement of a binder based on nitrocellulose dissolved in amyl acetate and diethyloxalate by the NTs-62 nitrolacquer with solvent no. 646 is found to ensure the production of high-quality protective coatings by the slip method using aluminizing and aluminosiliconizing. Isothermal heat-resistance tests in air at 1100°C for 200 h have confirmed high protective properties of the coatings fabricated by aluminizing and aluminosiliconizing. Using the Davidenkov method, we find that residual compressive stresses at a depth of 20–30 μm are induced in the coatings fabricated by aluminizing and aluminosiliconizing by the slip method with the new binder composition (NTs-62 lacquer + solvent no. 646).