High-temperature strength of Ni-base superalloy coatings

Recently considerable attention has been paid to large utility gas turbines, because of their high efficiency and many other advantages. This accelerates the introduction of advanced superalloys and coatings. While these technologies are traditionally from aero turbines, many novel challenges have arisen in their application, e.g. long operating time, weight, cyclic duty, environment using cheaper fuel, and size. This paper describes the mechanical properties and failures of the superalloys and the coatings used at the hot sections of utility gas turbines. Special focus is put on thermo-mechanical fatigue failure, and the collaborative test results by the Subcommittee of “Superalloys and Coatings ” in The Society of Material Science, Japan, is introduced.