航空航天铝合金腐蚀疲劳研究进展

Research Progress on Corrosion Fatigue of Aerospace Aluminum Alloy

铝合金因具有高的比强度、比模量,好的加工性能及焊接性能,在航空航天领域应用广泛。而腐蚀疲劳是造成航空航天材料失效的重要原因之一,因其危害性高、破坏性强且难以提前预测等特点,受到了广泛关注。铝合金腐蚀疲劳问题一直是飞机日历寿命研究中的重点问题,随着可重复使用航天器理念的提出,多次空天往返和地面修复过程也使腐蚀疲劳问题在可重用航天器上不可忽视。综述了近年来航空航天铝合金腐蚀疲劳的研究现状,从航空铝合金腐蚀疲劳机理的角度,归纳了腐蚀疲劳裂纹萌生和扩展机制。从腐蚀疲劳环境模拟和腐蚀环境等效两方面,介绍了目前主要的实验室腐蚀疲劳试验技术。分别从材料因素、环境因素和力学因素,分析对腐蚀疲劳裂纹扩展及寿命的影响。重点关注了腐蚀疲劳交替形式下疲劳寿命的特点。提出了在多因素共同影响下的腐蚀疲劳裂纹扩展、损伤演化和寿命预测,以及加速腐蚀环境的当量等效。试验与模拟的有机结合,是今后铝合金腐蚀疲劳的重要发展方向。

Aluminum alloys are widely used in the aerospace field due to their high specific strength,specific modulus,good workability and welding performance.Corrosion fatigue is one of the important reasons for the failure of aerospace materials.It has attracted wide attention because of its high harmfulness,strong destructiveness and difficulty in predicting in advance.The corrosion fatigue of aluminum alloy has always been a key issue in the study of aircraft calendar life.With the concept of reusable spacecraft,multiple air-to-air round trips and ground repair processes have made corrosion fatigue problems on reusable spacecraft not to be ignored.Overviews the research status of corrosion fatigue of aerospace aluminum alloys in recent years,summarize the mechanism of corrosion fatigue crack initiation and propagation from the perspective of corrosion fatigue mechanism of aviation aluminum alloys,introduces the main laboratory corrosion fatigue test technology from two aspects of corrosion fatigue environment simulation and corrosion environment equivalent.It analyze the effects of material factors,environmental factors and mechanical factors on corrosion fatigue crack growth and life,focusing on the characteristics of fatigue life under the alternate form of corrosion fatigue.It is proposed that corrosion fatigue crack growth,damage evolution and life prediction under the combined influence of multiple factors,as well as the equivalent equivalent of accelerated corrosion environment,and the organic combination of test and simulation are important development directions for aluminum alloy corrosion fatigue in the future.