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There is an increasingly urgent need of lightweight components in aerospace industry, among which aluminum (Al) alloys have been the optimal materials of choice for aircraft structural parts since being used in the Junkers F.13 aircraft in the 1920s. Compared to other metal materials, Al alloys have a lower density, and the use of Al alloys reduces the total weight of the aircraft and improves fuel efficiency and load capacity. Meanwhile, the strength and hardness of Al alloys with alloying and heat treatment can be significantly enhanced for uses in high loads and vibration environments. Furthermore, in the harsh aerospace environment, aircraft may receive various climatic conditions and chemical corrosion. Due to good corrosion and fatigue resistance, Al alloys demonstrate excellent performance under these conditions, ensuring the long–term service life of aircraft. In addition, Al alloys have good recyclability, and they can be recycled to reduce resource consumption and environmental load, in line with the principle of sustainable development. In recent years, although composites have been widely used in aerospace, high–strength Al alloys are still in an indispensable position. Therefore, this article reviews the progress and applications of Al alloys commonly used in aerospace. The common strengthening methods and advanced manufacturing and processing technologies of Al alloy are also discussed, which can provide references for the development of advanced high–performance aviation Al alloys in the future.

Cold/hot forming wrought Al components with the apparent advantage of lightweight, outstanding formability and strength-ductility synergy are promising in structural materials field. Recrystallization is an indispensable process during deformation or heat treatment, whose driving force and microstructures have great relevance with the mechanical properties. In recent years, reinforcement and intermetallic particles have attracted great interests in precise intervening and controlling of recrystallization microstructures due to their immense potentials in regulating the driving and retarding force of recrystallization. Nevertheless, optimizing recrystallization microstructures of particle tailored wrought Al alloys is highly challenging due to the numerous affecting factors of particles (e.g., particle addition method, size, morphology, spatial distribution, coherency, and content, etc.) and the different driving force of static and dynamic recrystallization. To further impel the progress of recrystallization process of wrought Al alloy, this review gives an in-depth cognition of the roles of intermetallic and ceramic particles in recrystallization process of wrought Al alloys. The potential relevance between the particle characteristics, recrystallization driving force, and recrystallization microstructures in wrought Al alloys are summarized. The influences of regulated recrystallization microstructures on mechanical properties of wrought Al alloy are also overviewed. This review contributes to the comprehensive understanding of mechanisms of particle manipulated recrystallization evolution, and the future research orientations and development opportunities are prospected.

Incident Ti–Si poisoning when applying traditional agents of microstructure manipulation in Al–Si alloys is always adverse to realize multilevel microstructure control. This work combined the manipulation by physically formed in-situ nano-ceramics from Fe79.58B11.26Si9.26 amorphous alloy and the micro-alloying to comprehensively improve the microstructure configuration of Al–7.0Si–4.0Cu alloy. It was suggested that micro-alloying of Mg and Sb prominently refined α-Al dendrites and eutectic silicon. Micro-alloying with Mg increased the nucleating temperature of α-Al, meanwhile Mg atoms can hinder the growth of α-Al and eutectic silicon. Sb atoms can also be adsorbed to the growth interfaces of eutectic silicon hindering the growth process. On this basis, trace Fe79.58B11.26Si9.26 amorphous alloy brought further optimization on α-Al dendrites and eutectic silicon, especially Al2Cu and Mg2Si, realizing the multilevel microstructure control. In-situ Fe2B and Fe3Si nano-ceramics were confirmed to have low lattice misfits with α-Al and silicon, serving as efficient nucleation sites and growth retardants. After combined micro-alloying and manipulation, the mean sizes of α-Al and eutectic silicon were significantly refined by 72.7% and 79.9%, respectively, meanwhile, the ultimate tensile strength (UTS) and plastic strain (δ) were improved to 480 MPa and 9.4%, corresponding to 30.1% and 77.4% improvement, respectively. This work provides new mentality to realize multilevel microstructure control and improvement of strength–toughness synergy in Al–Si alloys.

Trace in situ nanocrystals crystallized from metallic glasses as innovative microstructure manipulation agents were proposed to manipulate the multilevel microstructure configuration of eutectic Al–Si13.0–Cu5.0–Mg0.6 alloy. And the manipulation effect by nanocrystals for different times was compared with Sr, nanocrystals + Sr and Ni alloying. The calculations indicated that NiTi nanocrystals had an ideal mismatch with α-Al and silicon; thus, nanocrystals can stimulate their nucleation and hinder their growth. Sr and Ni alloying were found to only refine the silicon phases, but nanocrystals refined both α-Al and silicon phases. Moreover, the inhibition of nanocrystals and Sr was verified. After the manipulation by nanocrystals for 20 min, the optimum microstructure configuration and mechanical properties were realized. The results showed that the size of α-Al was reduced by 86.7%, and the size and aspect ratio of eutectic silicon were decreased by 27.7% and 50.0% compared with that of the unmanipulated alloy. Primary silicon was distributed more evenly and reduced in number. In addition, the size of Al2Cu and Mg2Si was decreased by 57.7% and 90.6%. Accordingly, a prominent microstructure configuration comprised of refined α-Al, silicon phases and precipitations was established successfully via nanocrystals. Moreover, the ultimate tensile strength (UTS) and fracture strain (FS) were increased by 17.8% and 73.3% compared with that of the unmanipulated alloy at ambient temperature, and the yield strength (σ0.2) and UTS were increased by 21.5% and 14.4% at 250 °C. The specific strengthening mechanisms were revealed, as well. Therefore, in situ nanocrystals have great application potential and developmental value.