Evolution of Ni-based superalloys for single crystal gas turbine blade applications

The chemistry of the Ni-based superalloys designed for single crystal gas t urbine blades has significantly evolved since the development of the first generation of alloys derived from columnar grained materials. Thr overall p erformance of the second and third generations has, been significantly impr oved by the addition of increasing amounts of rhenium. However, the problem s of increased density, grain defects and microstructural stability have al so become more and more acute and render necessary to carefully control the level of the various alloying elements in order to effectively benefit fro m the: high potential of the most recently developed third generation alloy s. (C) 1999 Editions scientifiques ct medicales Elsevier SAS.