In this paper, the effects of material removal strategies and initial stress states on the machining deformation of aluminum alloy plates were investigated through a combination of finite element simulation and experiments. We developed different machining strategies described by Tm+Bn, which removal m mm materials form top and n mm materials from the bottom of the plate. The results demonstrate that the maximum deformation of structural components with the T10+B0 machining strategy could reach 1.94 mm, whereas with the T3+B7 machining strategy was only 0.065 mm, decreasing by more than 95%. The asymmetric initial stress state had a significant impact on the machining deformation of the thick plate. The machined deformation of thick plates increased with the increase in the initial stress state. The concavity of the thick plates changed with the T3+B7 machining strategy due to the asymmetry of the stress level. The deformation of frame parts was smaller when the frame opening was facing the high-stress level surface during machining than when it was facing the low-stress level. Moreover, the modeling results for the stress state and machining deformation were accurate and in good accordance with the experimental findings.

The 7085 aluminum alloy with a low Cu content is an important lightweight structural material in the aerospace field due to its advantages of low density, high specific strength, and high hardenability. However, like other high-strength Al-Zn-Mg-Cu alloys, this alloy is susceptible to stress corrosion cracking (SCC). Additionally, the lower Cu content may increase its tendency toward SCC, potentially impacting the safe use of this alloy. Therefore, this study investigated the effects of aging treatment processes on the mechanical properties and SCC resistance of 7085 aluminum alloy. And the factors affecting the properties of the alloy were analyzed by optical microscope (OM), scanning transmission electron microscope (STEM), and energy-dispersive X-ray spectroscopy (EDS) analyses. The results indicated that increasing the secondary aging temperature and adding a tertiary aging step can significantly reduce the alloy’s susceptibility to SCC while meeting the mechanical performance requirements. The reduced SCC sensitivity was mainly attributed to the increased spacing of grain boundary precipitates, a wider precipitate-free zone at the grain boundaries, and a higher Cu content in the grain boundary precipitates.

The high-Mg-content Al-Mg-Zn-Si alloy, as a novel aluminum alloy, exhibits excellent strength, toughness, and corrosion resistance, demonstrating significant application potential in lightweight structural components for aerospace, weapon systems, rail transportation, and other fields. In this study, friction stir welding was employed to weld the high-Mg-content Al-Mg-Zn-Si alloy. Subsequent aging treatment was applied to establish the relationship between the mechanical properties and microstructural characteristics of the welded joint, aiming to elucidate the strengthening mechanisms of the new alloy and provide insights for achieving high-quality welds. The results indicate that the microhardness profile of the as-welded joint exhibited a “W” shape, with overall low hardness values and minor differences between zones. After the aging treatment, the microhardness increased significantly in the base material (BM), the thermo-mechanically affected zone (TMAZ), and the stir zone (SZ), whereas the heat-affected zone (HAZ) adjacent to the SZ exhibited only a marginal increase, making it the softest region in the aged joint. The yield strength and ultimate tensile strength of the aged joint increased to 327 MPa and 471 MPa, respectively. The enhancement in microhardness and strength after aging treatment was attributed to the precipitation of numerous nano-sized T-phase particles within grains. Interestingly, the tensile samples of the aged joint fractured in the high-hardness SZ instead of the low-hardness HAZ. This fracture behavior was primarily attributed to continuous grain boundary precipitates, which reduced intergranular cohesion. In contrast, the elongated grain structure in the HAZ more effectively resisted intergranular crack propagation compared to the equiaxed grains in the SZ.

In this study, we investigated the hot deformation behavior and microstructural evolution of a novel high-magnesium-content (high-Mg) aluminum alloy, bridging the disciplines of material processing and physical metallurgy. Uniaxial hot compression tests were performed over the temperature range of 280~400 °C and strain rates of 0.001~10 s⁻¹ to investigate its hot deformation behavior. The flow stress curves were systematically analyzed, and a constitutive model was developed to describe the thermo-mechanical response of the alloy. Microstructural evolution was characterized using scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). The results indicate that dynamic recovery serves as the dominant softening mechanism at lower deformation temperatures (≤320 °C). As the temperature increased to 400 °C, a significant rise in dynamic recrystallization was observed. Moreover, at 400 °C, higher strain rates led to the formation of abundant, network-like, mushroom-shaped dynamically recrystallized grains.

This study investigates the machining deformation of thick aluminum alloy plates, specifically in aerospace frame components, focusing on the influence of asymmetric residual stress states and machining strategies. Aluminum alloys are commonly used for large structural components due to their strength, formability, and corrosion resistance. However, machining these components often leads to deformation caused by residual stress release, cutting forces, and thermal effects. Using finite element simulations and experimental validation, the study analyzes how asymmetric residual stresses, induced by spray quenching, affect deformation patterns during machining. It is found that lower initial stress asymmetry results in less deformation, while machining sequences that optimize stress release significantly reduce the final distortion. Among the strategies tested, the diagonal milling sequence yielded the smallest deformation, achieving a reduction of up to 4%. The study concludes that both the initial residual stress state and the machining strategy are critical in controlling deformation, offering insights for improving machining processes in aerospace manufacturing to enhance precision and reliability.

Al-Li alloys can be strengthened by pre-stretching before artificial aging to promote the precipitation of the strengthened phase. This study investigates the mechanical properties and evolution of a 2 mm thick Al-Cu-Li alloy sheet’s microstructure with various pre-stretching degrees. From the results, as the degree of pre-stretching is increased, the strength gradually increases. Particularly noticeable is the upward trend in yield strength. By the pre-stretching volume of 4%, tensile strength can be enhanced by 95 MPa and yield strength by 187 MPa. Pre-stretching leads to a gradual reduction in precipitation of θ′, an increase in T₁ phase number density but a reduction in T₁ phase diameter. Meanwhile, a combination of strain-hardening and precipitation-strengthening determines the yield strength. Increasing the pre-stretching degree increases strain-hardening, while T1 phase strengthening decreases gradually.