Thermal spray manufacturing issues in coating IGT hot section components

The desire to improve the performance of gas turbine engines has led to hig her operating temperatures in the turbine sections of the engine. Materials used for hot section turbine blades and vanes are not resistant to hot cor rosion, and therefore require protective coatings. This paper reviews the c urrent art and technology of thermally sprayed MCrAlY and TB coatings onto hot section components. The issues in applying such coatings will be discus sed, along with references to manufacturing issues on the shop floor. The d ifficulties inherent in applying a line-of-sight coating to complex geometr ies will be discussed. The testing, evaluation, and performance characteris tics of typical coatings are discussed.