Ti–N multilayer systems for compressor airfoil sand erosion protection

Frequently aircraft, tank and helicopter gas turbine engines are operated in a desert environment where the gas turbine compressor rotor blades and vanes are exposed to erosive media such as sand and dust. Base metal erosion leads to increased fuel consumption, efficiency loss, and can cause damage to compressor and turbine hardware. Erosion resistant coatings such as Ti–N, Ti–C–N, Ti–Zr–N, Ti–Zr–C–N, Ti–Al–N, and Ti–Al–C–N applied by cathodic arc physical vapor deposition or other PVD processes can be used to prolong the life of compressor airfoils in a sand erosion environment. Praxair Surface Technologies, Inc. has developed unique multilayered Ti–N coating systems with optimized erosion resistance compared to conventional single layers. The multilayer structure can be tailored to the erosion media particle size distribution. The key features of two selected coating architectures are outlined. Selected erosion performance data with different erosion media are presented. And finally the aspects to ensure high quality mass production are addressed.