The service damage mechanism of K403 Ni-based superalloy turbine blade with the aluminized coating are investigated systematically. Fracture morphologies are inspected with a failure event, and the microscopic damage mechanisms are explored based on the aluminized blades with different operation times. It concludes that the formation of massive pores, aggregation of bulk carbides, coarsening and breaking of σ phases, development of continuous γ′ film, etc, lead to the multi-source fatigue cracking at the interface, with the grain boundaries and Kirkendall non-contact areas as the propagation channels, resulting in the rapid fatigue failure and significant life reduction of aluminized turbine blades.

系统研究了镀铝涂层K403镍基高温合金涡轮叶片的服役损伤机理。通过失效事件检查断裂形态，并基于不同操作时间的镀铝叶片探索微观损伤机制。认为大量孔隙的形成、块状碳化物的聚集、σ相的粗化和断裂、连续γ′膜的发展等导致界面处多源疲劳开裂，晶界和Kirkendall非接触区域作为传播通道，导致镀铝涡轮叶片的快速疲劳失效和显着降低寿命。