摘要：针对某发动机风扇静子叶片在工作时发生的下缘板掉块故障，通过对故障叶片进行宏观检查、断口分析、磨痕截面检查、材质分析以及结构受力分析等工作，确定了叶片掉块的性质和产生原因。结果表明：叶片掉块性质为多条单源线性起始的疲劳裂纹开裂汇聚而成，疲劳起源于叶片下缘板与内环下配合面靠近叶背侧表面的偏磨区域。叶片与机匣和内环的径向配合间隙偏大，导致叶片与内环配合位置非均匀接触和偏磨，进而产生微动疲劳损伤，是导致叶片掉块的主要原因。通过分析，排除了叶片材质及冶金缺陷等因素造成叶片掉块的可能性。基于此，提出了适当减小叶片与机匣、内环的径向配合间隙，以及在配合面喷涂铜铝涂层的改进建议，以避免类似故障再次发生。
Abstract:In this paper, the falling block fault of fan stator blade of an aero-engine occurred during working. The property and cause of falling block were identified by visual inspection, fracture analysis, profile inspection, material analysis, and structural force analysis. The results indicated that the property of blade falling block was the convergence of several single source linear starting fatigue cracks, and the fatigue originated from the eccentric wear area of the lower edge plate and the lower mating surface of the inner ring near the back surface of the blade. The main cause of blade falling block was the radial fit clearance between the blade and the inner ring was too large, which lead to the non-uniform contact and eccentric wear of the fit position between the blade and the inner ring, and then the fretting fatigue damage occurred. Through the analysis, the possibility of blade falling block caused by material factors and metallurgical defects was excluded. Based on this, suggestions were put forward to appropriately reduce the radial fit clearance between the blade and the casing, the inner ring, and to spray the copper-aluminum coating on the fit surface, so as to avoid similar failures.
 

风扇静子叶片；掉块；疲劳裂纹；偏磨；微动疲劳