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 f...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.展开更多
Recrystallization behavior during optimized heat treatments provides a potential to obtain desirable grain structure,which significantly improves the mechanical properties of aluminum alloys.The influence of grain str...Recrystallization behavior during optimized heat treatments provides a potential to obtain desirable grain structure,which significantly improves the mechanical properties of aluminum alloys.The influence of grain structures on fatigue crack propagation(FCP)behaviors of Al-Cu-Li alloy with hot-rolled(HR)and cold-rolled(CR)was investigated.Subgrain boundaries have a significant impact on small crack growth rates,which is reflected in the pronounced fluctuation of fatigue crack growth of HR specimens after solution treatment.Moreover,the specific cellular structure within grains can improve the deformation capacity of alloys due to their accommodation of plastic deformation,which contributes to the lower fatigue crack growth rates and higher threshold values in HR specimens.The intragranular deflection also decelerates the FCP rate and occurs in these regions of large grain without subgrain boundaries.Recrystallization occurs in the CR specimens,resulting in small anisotropy on the fatigue resistance for the different orientations in the Paris stage due to the recrystallization texture.Fatigue cracks can be deflected and tend to propagate along the grain boundaries when it goes into the grain with a relatively low Schmidt factor value.展开更多
基金co-supported by the National Natural Science Foundation of China(Nos 52475346 and U21A20130)the Natural Science Foundation of Hunan Province,China(No.2023JJ10019)+1 种基金China Postdoctoral Science Foundation(No.2022M712642)Hunan Science and Technology Innovation Plan,China(2023RC1068)。
文摘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.
文摘Recrystallization behavior during optimized heat treatments provides a potential to obtain desirable grain structure,which significantly improves the mechanical properties of aluminum alloys.The influence of grain structures on fatigue crack propagation(FCP)behaviors of Al-Cu-Li alloy with hot-rolled(HR)and cold-rolled(CR)was investigated.Subgrain boundaries have a significant impact on small crack growth rates,which is reflected in the pronounced fluctuation of fatigue crack growth of HR specimens after solution treatment.Moreover,the specific cellular structure within grains can improve the deformation capacity of alloys due to their accommodation of plastic deformation,which contributes to the lower fatigue crack growth rates and higher threshold values in HR specimens.The intragranular deflection also decelerates the FCP rate and occurs in these regions of large grain without subgrain boundaries.Recrystallization occurs in the CR specimens,resulting in small anisotropy on the fatigue resistance for the different orientations in the Paris stage due to the recrystallization texture.Fatigue cracks can be deflected and tend to propagate along the grain boundaries when it goes into the grain with a relatively low Schmidt factor value.
