Structural changes and mechanisms of thermal fatigue crack generation in high-temperature alloys with coatings

Degradation of the surface layers of superalloys and thermal-fatigue damage to the structural elements of gas-turbine engines

“…In directionally crystallized alloys, the cracks are initiated from the grain boundaries transversely oriented relative to the line of action of the loads [10]. At the same time, in monocrystalline alloys, the cracks are initiated from the eutectic phase and carbides [10].…”

“…In directionally crystallized alloys, the cracks are initiated from the grain boundaries transversely oriented relative to the line of action of the loads [10]. At the same time, in monocrystalline alloys, the cracks are initiated from the eutectic phase and carbides [10]. The results of experimental investigation of damage and the kinetics of thermal fatigue cracks carried out on wedge-shaped specimens depending on the thermal and stressed states of workpieces can be found in [11][12][13][14].…”

“…The mechanisms of damage to the surface layers, initiation and propagation of thermal fatigue cracks in structural elements of GTE are investigated in [10][11][12]. In directionally crystallized alloys, the cracks are initiated from the grain boundaries transversely oriented relative to the line of action of the loads [10].…”