Review on Strategies for Inhibiting Interdiffusion Between Protective Coatings and Superalloys Under High Temperature Oxidation

The service of protective coatings at high temperature will lead to interdiffusion between the coating and superalloy. The occurrence of interdiffusion not only reduces the oxidation resistance of the coating but also reduces the mechanical properties of superalloys, especially single crystal superalloys. At present, the main methods of suppressing interdiffusion are: adding a diffusion barrier layer between the coating and superalloy, a so-called "equilibrium" (EQ) coating, and a nanocrystalline coating. In the current review, the advantages and disadvantages of these three methods for suppressing interdiffusion are discussed, and an attempt is made to determine the best method for suppressing interdiffusion to improve the service life of high-temperature components.