Review of key issues on coating against sand erosion of aero-engine compressor blade

Military helicopters and transporters have to take off and land under harsh conditions like deserts or battle fields and engines' sucking in solid grains in these complicated environments leads to engine erosion, which in turn severely influences the reliability of the engine and causes reduced performances of the aircraft. Depositing anti-erosion coatings is an effective way to improve the performances of compressor blades against sand erosion. However, under severe erosion environment, coatings are facing great challenges. In order to improve the anti-erosion performances of the coatings, several key issues should be addressed, which include improving coating's adaptability to the environment, designing effective arrangement of components for the coating, devising more effective coating production methods and reliable testing mechanisms. Through analyzing the case of the severe erosion of US helicopter engines in their operations in west Asian desert, this paper reviews the three key issues in coating performance improvement which are the design of coatings, methods of coating production and erosion testing mechanisms. A comparative analysis reveals that the poor erosion mechanism study, lacking of coating design method, incomplete erosion test and unsystematic research are the major problems which result in the fact that the existing erosion coating technology cannot be used on compressors of aircraft in China. This paper is significant for deciding future developments and research focuses of anti-erosion coatings in China.