客机排污口支架断裂失效分析

Fracture Analysis on Drain Bracket of Aircraft

运用外观检查、断口宏微观形态观察、微区能谱分析以及金相检查等技术手段对支架断裂情况进行分析。结果表明:后排污口支架的断裂性质为铝合金剥离晶间腐蚀失效,支架表面涂层局部受到破坏,裸露基体与污水直接接触是导致支架发生剥离腐蚀的直接原因;而短横方向的变形组织则降低了材料抗腐蚀能力。

The failure mode and cause of aircraft bracket was studied by macro and micro observation, EDS analysis and metallurgical structure examination. The results show that the fracture of the bracket is exfoliation corrosion crack. Local coating on the bracket was damaged, and the bare regions contact directly with the waste water, which is the main cause for the exfoliation corrosion of the bracket. In addition, the deformation structure in the S direction decreases the corrosion resistance of the material. According to the results above, some measures for the safe of aircraft were put forward.