The Effect of Surface-Layer Modification of Nickel Alloys on the Heat Resistance of Aluminide Coatings Applied on Gas-Turbine Blades

A method for the preparation of a complex diffusion coating by preliminary saturation of the surface layer of heat-resistant nickel alloys with nickel and by subsequent chrome aluminizing in vacuum using powder mixtures at processing temperatures of 1000 and 1200°C is analyzed. The characteristics of the chemical composition and structure of coatings and comparative data on the heat resistance at temperatures of 1000, 1050, and 1100°C under the conditions of isothermal oxidation are given. It is shown that the complex coating exhibits increased heat resistance owing to an increase in the uniformity of the surface alloy layers obtained by the diffusion nickel plating.