Study on Vibration Fatigue of Working Blades with High Vortexes Based on Abrasive Flow

The high vortex working blade has defects such as remelted layer and prismatic marks on the edge of the hole under the state of electrical discharge machining and high-power femtosecond laser drilling. The abrasive flow treatment can effectively remove the remelted layer and improve the rounding of the hole edge. The study was performed by comparing the vibration fatigue performance and fracture damage behavior of simulated parts and blades before and after the abrasive flow treatment. The results show that the high-temperature vibration fatigue failure of the blade is located in the relatively large bending stress area of ​​the blade root, and the structural stress does not change before and after the abrasive flow treatment. After the abrasive flow treatment, the origin of the blade cracks changed from the original angle source on the inlet side of the inner wall in the air film hole and the small line source of the hole-making defect in the middle of the hole wall to only the angle source on the inlet side of the inner wall in the air film hole. Also, there is a guide hole at the edge, which improves the local stress and improves the high-cycle fatigue reliability of the blade. The crack propagation mode before and after the abrasive flow treatment is similar: they both propagated obliquely at 45° along the thickness and width of the blade after the initiation of crack, which is the same with the vibration fatigue expansion mode of single crystal materials or plates. After that, it expands in multiple directions along the leading edge, trailing edge, and ribs. The early expansion shows a cleavage-like feature, and a wide fatigue strip can be seen in the middle and late expansion.