Thick Nanostructured, Erosion-Resistant PVD Coatings for Metallic Turbine Blade Materials

The Air Force is seeking optimized physical vapor deposition (PVD) coating solutions to mitigate sand ingestion of modern aircraft engines, which causes severe erosion, high turbine-engine maintenance costs, and reduced efficiency. Engine manufacturers are developing blisk components from steels and advanced Ti alloys to reduce weight, part count, manufacturing costs, and fretting wear from an integrated construction. However, Ti alloys need surface protection to increase their poor erosion resistance. Also, due to the varying angles of the airfoil surfaces, the impingement angle of erodent will change as a function of position on the blisk blades. To address these concerns, Engineered Coatings, Inc. and Southwest Research Institute (SwRI) propose to demonstrate thick, dense nanostructured PVD coatings fabricated by an enhanced plasma processing method. These nanostructured coatings offer demonstrated improvements in sand-erosion resistance. The combination of the enhanced plasma processing method and component translation will enable complex part coverage. Coating screening will include indentation adhesion/toughness measurements, thermal cycling, screening erosion tests, and final erosion testing in a representative environment. In the final task of the program, a blisk component or section will be coated with the nanostructured coating to demonstrate part fixturing and translation during coating application.