某型飞机对接螺栓微动疲劳裂纹分析

摘要

The causes of certain type aircraft connecting bolt failure were analyzed with fracture inspection, X-ray energy analysis, and trace analysis. The results showed that the causes are fretting fatigue crack, and cadmium embitterment; cadmium embitterment is further induced by fretting fatigue cracks. The fretting fatigue cracks presented before the aircraft was overhauled, and cadmium penetrated into the inner of fretting fatigue cracks during cadmium plating of complete overhaul, and then the cadmium embitterment happened in service.%通过断口形貌观察、X射线能谱检测、痕迹分析等试验方法,对某型飞机对接螺栓产生裂纹的原因进行了分析.结果表明,对接螺栓的裂纹性质为微动疲劳裂纹；表层微动疲劳裂纹产生后,进一步发生了镉脆开裂；微动疲劳裂纹在飞机末次大修前就已形成,在大修镀镉时镉渗入裂纹内部,并导致了对接螺栓在大修后的使用中裂纹发生镉脆扩展.