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The hot deformation behavior and dynamic softening mechanism of 7B50 aluminum alloy were studied via isothermal compression experiments in the range of 320–460 °C/0.001–1.0 s−1. According to the flow curves obtained from the experiments, the flow behavior of this alloy was analyzed, and the Zener–Hollomon (Z) parameter equation was established. The hot processing maps of this alloy were developed based on the dynamic material model, and the optimal hot working region was determined to be 410–460 °C/0.01–0.001 s−1. The electron backscattered diffraction (EBSD) microstructure analysis of the deformed sample shows that the dynamic softening mechanism and microstructure evolution strongly depend on the Z parameter. Meanwhile, a correlation between the dynamic softening mechanism and the lnZ value was established. Dynamic recovery (DRV) was the only softening mechanism during isothermal compression with lnZ ≥ 20. Discontinuous dynamic recrystallization (DDRX) becomes the dominant dynamic recrystallization (DRX) mechanism under deformation conditions of 15 < lnZ < 20. Meanwhile, the size and percentage of DDRXed grains increased with decreasing lnZ values. The geometric dynamic recrystallization (GDRX) mechanism and continuous dynamic recrystallization (CDRX) mechanism coexist under deformation conditions with lnZ ≤ 15. [ABSTRACT FROM AUTHOR]

The orientation relationship (OR) between Al matrix and several typical inclusions, Al2O3, MgO, AlN, TiB2, and AlB2, in Al alloy have been studied by edge-to-edge matching model and refined with Δg theory. Based on the calculation of interatomic spacing misfit and interplanar spacing misfit, the number of ORs between Al and Al2O3, MgO, AlN, TiB2, AlB2 were predicted to be 1, 7, 2, 2, and 2, respectively. The result reveals that the wettability of Al to the studied inclusions could rank as MgO, AlB2, TiB2, AlN, Al2O3 in the order of decreasing, and the removability of those particles from aluminum melt rank in an opposite way from the perspectives of crystallography features of interfacial energy. Moreover, Al2O3 have a higher sensitivity to the performance of a processed aluminum alloy component than other inclusions, and MgO has the minimal impact, when the studied inclusions were residual in aluminum alloy. [ABSTRACT FROM PUBLISHER]

In this work, ab initio molecular dynamics (AIMD) simulations under both NVT and NPT ensembles were performed to study the influence of alloying elements of Mg, Fe, Si, Ti, Cu, Zn, F, and Cl on the H diffusion behavior in liquid aluminum melt. It is found that the diffusion coefficient of H simulated by AIMD under the NVT model is highly consistent with the reported experimental results. Specifically, the addition of Cu, Cl, Si, and Zn is inclined to increase the diffusion coefficient of H in the melt, whereas the opposite result is observed with the addition of F, Fe, and Ti. Moreover, it is proved that the H diffusion coefficients are positively correlated with the H-Al bond lengths and the coordination number of H in a constant volume system. The obtained results deepen the understanding of the diffusion of H atoms in Al melts and contribute to the optimization of existing melt purification technologies. • The effect of alloying elements on hydrogen diffusion behavior in the melt was studied by ab initio molecular dynamics. • The effect of the addition of the alloying elements on the arrangement of Al atoms in the melt is discussed. • The H diffusion coefficient is proved related to the rearrangement of Al atoms caused by elemental additions. [ABSTRACT FROM AUTHOR]

The effects of silver (Ag) alloying and a retrogression re-aging heat treatment on the mechanical properties and electrical conductivity of the Al–Zn–Mg–Cu aluminum alloy were studied by means of tensile test, electrical conductivity test, and transmission electron microscopy (TEM). A trade-off between the mechanical strength and electrical conductivity was achieved, with the former reaching 558 MPa and the latter reaching 45.1 IACS. The alloy was prepared through a retrogression re-aging heat treatment (120 °C/6 h + 160 °C/7 h + 220 °C/0.5 h + 120 °C/24 h) performed on the solution and quenched samples. Furthermore, through TEM analysis of the sample solution treated at Temperature Ⅰ (420 °C/3 h + 470 °C/2 h) and Temperature II (420 °C/3 h + 480 °C/2 h), indicates that the Ag interacts with zinc or magnesium to form small clusters, which can act as precursors for η′ precipitates. η–type precipitates were the dominant precipitated phase, and the precipitation sequence was supersaturated solid solution (SSS)→ small clusters → Guinier–Preston (GP) zone → η′ → η. Furthermore, after the retrogression re-aging heat treatment, a large amount of GP (Ⅱ) and η′ precipitated in the matrix. GP (Ⅱ) and the η′ phase are related to the precipitation of {111} Al crystal plane, it is thus speculated that the interaction between the η′ phase and GP (Ⅱ) or nanosized Al 3 Zr dispersoids contributes to the strength of the alloy. Moreover, the retrogression re-aging heat treatment promotes the precipitation of the second phase, which can purify the matrix and reduce lattice distortion, thus improving the conductivity of the alloy. [ABSTRACT FROM AUTHOR]

The effect of homogenization on the corrosion behavior of 5083-H321 aluminum plates was studied. The intergranular corrosion, exfoliation corrosion, and electrochemical polarization, which are used to characterize the corrosion behavior of 5083-H321 aluminum alloy, were investigated. The results indicated that the samples that were not homogenized show superior corrosion resistance than the homogenized samples. The effects of the grain boundary character distribution, grain shape, and precipitates on corrosion are discussed on the basis of experimental observations. Omitting homogenization after casting is expected to have the optimal effect on the overall corrosion resistance of the material. [ABSTRACT FROM AUTHOR]