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The influence of three kinds of alloy adding 0.3–1.8 wt% Zn on the mechanical properties and corrosion resistance of medium Mg content 4.0–4.5 wt% (5083 type) hot rolled alloy was investigated. The results showed that the addition of Zn content could further dissolve the second phases into the matrix. The hardness and tensile strength were reduced when annealing at 250 °C × 2 h. The mechanical behavior of the alloys showed a tendency that increases first and then decreases and the peak reached its maximum when 1.6 wt% Zn is added at both annealed and unannealed states. Through quantitative analysis, the improvement of mechanical properties mainly comes from dislocation strengthening and Al–Mg–Zn ternary strengthening phases. Meanwhile, with the increase of Zn content, the intergranular corrosion (IGC) of the alloy improved greatly after annealing at 250 °C × 2 h. The electrochemical corrosion potential (ECP) of the alloys increased first and then decreased.

The effect of multi-stage solution on microstructure and properties was studied in Al–10.5Zn–2.05Mg–1.02Cu–0.2Zr–0.923Ti alloy extrusion. The microstructure, corrosion resistance, plasticity, hardness, and tensile properties of alloy were evaluated using metallographic microscope, X-ray diffraction analysis, micro-hardness tester, and microcomputer-controlled universal testing machine. The results show that the tensile strength and corrosion resistance of the alloy improve first and then deteriorate with increase of solution temperature and holding time, and 2# sample has the best mechanical properties (tensile strength is 711.159 MPa and elongation is 13%) and highest corrosion resistance of alloys. Furthermore, 2# sample has more uniform grains, more equiaxed crystals, and the low-angle grain boundaries, and the dislocation density and the dislocation strengthening contribution of alloy are relatively high. However, the grain grows and the dislocations were consumed with the increase of solution time and temperature, resulting in a decrease in dislocation density and dislocation strengthening contribution. It is indicated that alloy can achieve better comprehensive properties under solution treatment process (450 °C × 2 h + 460 °C × 2 h + 470 °C × 2 h + 480 °C × 2 h).