Microstructure Evolution and Property Enhancement of Hot-Rolled 5083 Aluminum Alloy During Homogenization Annealing

The 5083 aluminum alloy is widely used in marine engineering due to its excellent corrosion resistance and weldability. To address microstructural defects that may arise during hot rolling, homogenization annealing is employed as a critical post-processing step to enhance mechanical and processing properties. This study systematically investigates the effects of different homogenization annealing temperatures (held for 1 h) on the microstructure, corrosion behavior, and mechanical properties of hot-rolled 5083 aluminum alloy. The microstructural characteristics, phase composition, and corrosion morphology were characterized using scanning electron microscopy (SEM) with energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), polarized light microscopy (POM), electron backscatter diffraction (EBSD), and electrochemical tests. Microhardness was measured using a Vickers hardness tester. The results indicate that the annealing temperature markedly influences the type, morphology, and distribution of precipitated secondary phases and significantly affects grain refinement. The alloy treated at 350 °C (5083–350 °C) exhibited optimal corrosion resistance, as evidenced by electrochemical impedance spectroscopy showing the highest charge transfer resistance and surface morphology analysis revealing minimal and shallow corrosion pits. Simultaneously, this treatment achieved significant stress relief and secondary phase precipitation strengthening, resulting in a peak microhardness of 78.8 HV. The study demonstrates that 350 °C homogenization annealing synergistically improves both the corrosion resistance and mechanical properties of hot-rolled 5083 aluminum alloy, providing valuable insights for optimizing its heat treatment process.