Evaluation of Simple Aluminide and Platinum Modified Aluminide Coatings on High Pressure Turbine Blades After Factory Engine Testing-Round II

Abstract

This paper presents results of factory engine testing of simple aluminide and platinum modified aluminide coatings. Simple aluminide coatings were produced using pack cementation processes. Platinum modified aluminide coatings were produced using three aluminiding processes; pack cementation, above-the-pack or out-of-contact processing, and chemical vapor deposition. These coatings were evaluated on both directionally solidified and single crystal nickel base superalloy turbine blades. These high pressure turbine blades were tested in a commercial high bypass turbofan engine operating predominantly in a high temperature oxidation environment. Included in this paper are discussions of coatings phase stability, coating growth due to diffusion during engine operation, comparison of coating performance and assessment of remaining coating life after engine testing.