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The Vickers hardness time-temperature-properties (TTP) curve of aluminum alloy 7055 was evaluated by interrupted quench technique. The critical temperature range of TTP curve was determined from 210 °C to 420 °C with the nose temperature of 355 °C. The hardness decreased rapidly with isothermal duration in the critical temperature range. The hardness of aluminum alloy 7055 was predicted by quench factor analysis using the TTP curve and cooling curves. The predicted hardness agreed reasonably well with the measured results. The influence of time step and summation temperature range on the predicted results was studied. The cooling rate through the critical temperature range had dominant influence on the final hardness of the alloy.

The evolution of through-thickness strain gradients during snake rolling (SR), which introduces an horizontal offset between upper and lower rolls, of Al-Mg-Si-Cu sheets was investigated with the inscribed lines in side including rolling and normal direction of sheets. The complete pole figures were used to investigate the influence of such rolling on texture evolution. The results revealed that the SR rolled sheet developed a continuous through-thickness shear strain gradients and shear textures. The surface in contact with the slower roll (the lower roll) developed the largest shear strain and the strongest shear texture. While for the conventional symmetric rolling (CR), the sheet developed a small shear strain gradient which is symmetrical about the centerline of the sheet with nearly negligible shear strain and texture at the center of the sheet.

The influence of one- and two- stage solution heat treatment on the microstructure and mechanical properties of aluminum alloy 7055 was investigated. The results showed that in the case of one-stage solution heat treatment in the range of 450 °C to 470 °C, the strength increased while the ductility decreased with temperature. Further increasing temperature led to more dissolution of soluble constituents but a large amount of recrystallization, therefore, the strength decreased while ductility increased. The two-stage solution heat treatment, which included first stage of low-temperature-long-duration and second stage of high-temperature-short-duration heating was suggested for improvement of mechanical properties.

The response of microstructure in high strength Al-Zn-Mg-Cu aluminum alloy 7055 to Graff Sargent etchant was investigated. It was found that grain boundaries and subgrain boundaries were easily corroded due to presence of η phase, and grain boundaries were corroded more rapidly than subgrain boundaries. The grain structure could be revealed quite clearly after immersion for about 15s. S (Al2CuMg) and Al7Cu2Fe phase were quite stable during immersion if the time was not very long. A dealloying for Al/Mg in the S and Al7Cu2Fe phase was found after long time immersion. Prolonged immersion resulted in serious corrosion of subgrain boundaries, consequently separation of fine subgrains.