Characterization and modelling of Ni based superalloy materials with a dual layered MCrAlY coating system

Multilayered MCrAlY type coatings have the potential to be optimised to protect superalloy components against both corrosion and oxidation simultaneously. In this paper, a dual layered coating (NiCrAlY on top of a CoNiCrAlY coating) has been aged and the microstructural evolution has been observed and quantified using various electron microscopy based techniques. In addition, the microstructural evolution of the coating has been modelled using a diffusion based model capable of modelling the ageing of multilayer coatings. It is demonstrated that the model is reasonably accurate in predicting both the phase and chemical distributions through the coating system during ageing, and therefore has the potential to be used as a design tool for the improvement of future layered coating systems.