Corrosion fatigue mechanisms and control technologies in aviation aluminum alloys: A critical review
Yuqiang CHEN, He Zhang, Heng Li, Dingding Lu, Yufeng Song, Lihua Zhan, Suping Pan, Wenhui Liu
Abstract
Aviation aluminum alloys, primarily from the Al-Cu, Al-Zn-Mg-(Cu), and Al-Li series, have been widely applied over six decades, greatly advancing the aviation industry. However, their Corrosion Fatigue (CF) properties impede further advancements, prompting extensive research into their CF behaviors and underlying mechanisms. This review comprehensively evaluates previous studies on their development history, CF mechanisms, and key influencing factors. First, the historical evolution of aerospace aluminum alloys is summarized. Then, the currently recognized four crack initiation mechanisms and three crack propagation mechanisms are concluded, and the effects of external and internal factors on CF performance are discussed. The paper also reviews three methods and CF life prediction models for characterizing the CF behavior of aerospace aluminum alloys. Most existing studies on the CF behavior of aluminum alloys are based on the single corrosive environment, neglecting the fact that aircrafts experience multiple corrosive environments during service. However, the most critical scientific challenge is how to enhance their CF properties under increasingly demanding service conditions. For the purpose, this paper introduces advanced forming techniques based on the microstructural control, such as Equal Channel Angular Pressing (ECAP) and High-Pressure Torsion (HPT), aimed at laying the theoretical foundation for improving CF properties through microstructural regulation.