EBSD Analysis of Cyclic Oxidized Vacuum Plasma Sprayed MCrAlY Coatings

In order to prevent the metallic parts of industrial/aviation gas turbine from oxidation, MCrAlY overlay coatings and thermal barrier coatings were applied. MCrAlY overlay coatings form surface oxide layers at high temperature and oxidizing atmosphere and suppress diffusion of oxygen. In this results, MCrAlY coatings were formed on the Ni base superalloys by vacuum plasma spraying. MCrAlY coatings were subjected to cyclic oxidation treatment at 1000 ¡É for 1000 hours. Microstructures of oxidized MCrAlY coatings were analyzed by SEM and EBSD. As a number of cycles increased, the thickness of thermally grown oxide and ¥â-depletion layer were increased. Grain size of MCrAlY coatings increased with increasing oxidation cycles.