新型航空铝合金包铝层防腐有效期的确定

海洋环境下飞机结构腐蚀严重,合理确定铝合金包铝层防腐有效期,对于飞机日历寿命评估十分重要。根据实际环境数据编制的当量加速腐蚀试验谱,加速腐蚀约7 d与外场曝露1a相当。实验室条件下对某新型铝合金包铝材料进行当量10 a的腐蚀试验;采用KH-7700三维显微镜对腐蚀损伤进行观察和测量。结果表明,腐蚀7 a后,包铝层局部被腐蚀掉,丧失防腐功能。

Assessment of Corrosion Prevention Effective Service Life of Aluminum Alclad

It is very important to describe the corrosion damage evolvement rule of aircraft structure for evaluating calendar life.According to equivalent accelerated corrosion testing spectrum based on key environmental data,the corrosion damage of accelerating corrosion testing for 7 d is equivalent to that of field exposure for 1a.The new aluminum alloy of aircraft structure was accelerated tested for 10 a.Through KH-7700 3-D optical microscope,corrosion damage was inspected and measured.The result showed that some independent pits generate on the alclad surface in the first,and then many pits interconnect leading to the bigger holes.The effective service life of the aluminum alclad is 7 a under equivalent accelerated corrosion testing condition.