ALUMINIZING TURBINE PARTS – PROCESSES AND COATINGS
M. Thoma, C. Giolli, A. Giorgetti, A. Scrivani
Hot section gas turbine parts need protection against oxidation and hot corrosion. The essential element is Al to build the protective Al2O3. Al can be applied on the gas path surfaces by overlay techniques or by diffusion of Al into the base material – the “aluminizing“. Aluminizing can be done by slurry, pack cementation, out of pack, or by “pure“ CVD. Additional elements can be added to the aluminide.
The different techniques are discussed under the aspects of advantage/disadvantage, limits and possible coating structures.