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Al 6082 aluminum alloy has excellent corrosion resistance, strength, and formability. However, owing to the recrystallization effect of a hot working process, coarse grains form easily in this material, which reduces its strength and service life. The novel continuous casting direct rolling (CCDR) method can prevent the deterioration of this material. Thus, we used CCDR Al 6082 aluminum alloy as the research material in this study. By subjecting a CCDR Al 6082 aluminum alloy to heat treatment (T4 and T6) and cold rolling, the influence of recrystallization effect on its mechanical properties and on impact failure resistance were explored. The results demonstrated that the specimen subjected to T4 heat treatment had a higher elongation and that the specimen subjected to T6 heat treatment had a higher strength. After cold rolling, the hardness and strength of the specimens subjected to different heat treatments (coded T4R4 and T6R4) increased because of the work's hardening effect. Moreover, the elongations of both specimens decreased, but they were higher than the industrial standard (>10%). The strength of specimen T6R4 was higher (up to 400 MPa) than specimen T4R4. Moreover, relative to specimen T4R4, specimen T6R4 had greater tensile and Charpy impact failure toughness. [ABSTRACT FROM AUTHOR]

Currently, the primary commercial aluminum alloy fillers used are 4043 and 5356. However, when welded with high-strength work pieces like 6061 and 7075 aluminum alloys, the strength of weld beads significantly lags behind that of the original welded material. Both 4043 and 5356 aluminum alloys cannot be strengthened through heat treatment. The strength difference between the weld bead and base material doubles after heat treatment. In this study, an Al-Si-Cu-Mg alloy (SCM) filler modified using a heat-treatable A319 aluminum alloy was employed to investigate the post-welding microstructural and mechanical properties of specimens under room- and high-temperature conditions and after prolonged exposure in a saltwater environment (3.5 wt.% NaCl). The aim was to demonstrate that commercial aluminum alloy fillers could be substituted with a high-silicon aluminum alloy boasting excellent solidification and mechanical properties. The results revealed that, after heat treatment of the weld bead, dendrites were not eliminated, but the tensile strength increased to 310 MPa, closely matching that of commercial 6061 aluminum alloy. The strength of the weld bead remained higher than 250 MPa in high-temperature (240 °C) and saltwater environments. These findings underscore the potential application of this material. [ABSTRACT FROM AUTHOR]

Metal powder metallurgy (PM) is widely utilized in the tool and automotive industries due to its near-net forming advantages. While PM aluminum alloys have been explored in numerous studies, their practical engineering applications are still limited. Thus, this research delves into the nuanced aspects of PM Al-Si-Mg-Fe alloy. By employing hot-rolled dynamic recrystallization to control the metallurgical texture and introducing T6 treatment to refine the microstructure. These optimizations aim to enhance the properties of PM aluminum alloy materials. Results revealed that grain coarsening in the PM Al-Si-Mg-Fe alloy hampers the grain boundary strengthening effects, thus limiting the strength. Moreover, the solid-solution treatment applied to the PM specimens efficiently disperses silicon particles within the matrix, preventing the aggregation of silicon particles and the associated brittle effect caused by interface peeling. By implementing a three-stage process, sintering-rolling-T6 treatment, the rolled-T6 exhibited impressive tensile strength (291 MPa) and ductility (17 %), highlighting the excellent engineering applicability of PM Al-alloys. TEM analysis confirmed the presence of nanoprecipitation Al 3 Mg and Al 9 Fe 2 hard components within the matrix, contributing to the strength enhancement. These findings not only represent a significant milestone in the advancement but also provide valuable references for engineering applications in the field of PM Al-alloys. • PM technology enhances Al-Si-Mg-Fe alloy applications. • Three-stage process optimizes microstructure and properties. • Microstructural effects and phase distribution are compared. • Reveals Al 9 Fe 2 and Al(Si) 3 Mg strengthening mechanisms. [ABSTRACT FROM AUTHOR]