EFFECT OF MICROSTRUCTURE OF ALUMINIDE COATING ON HIGH-CYCLE FATIGUE PERFORMANCE OF COATING-SUPERALLOY SYSTEM

The high-cycle fatigue performance of different microstructures of aluminide coating-superalloy system has been studied at 900℃.The single phase coating of coarse equiaxialgrain NiAI(β)has unfavorable eJfect onJatigue life of the coating-superalloy.The fatigue lifemay shorten if the coating of NiAl(β)was an enrichment of coarse refractory metal grains.While an improvement can be made by dispersing numerous secondary phase particles such asextreme.fine γ′,quasi-σ-phase and others.