Deformation and strengthening behaviors of Al–Cu–Mg alloy thick plate during hot forming-quenching integrated process

The deformation and effective die quenching are critical to ensure the final dimensional accuracy and strength of the thick-walled curved components in hot forming-quenching integrated process. The deformation behavior of an Al–Cu–Mg alloy plate during bending-quenching process was thus analyzed at different temperatures and die clearances. The strengthening behavior along thickness and radial directions was evaluated under different heating and die quenching conditions. The strengthening mechanism was revealed by microstructure observation. It is found that the smaller die clearance and higher heating temperature contribute to improve the dimensional accuracy. The water-cooled die quenching can ensure the effective quenching of a bended specimen with 25 mm in thickness, being at the strengthening level of peak aging. And, the effective quenching thickness reaches 50 mm at least. Dynamic recovery is the main restoration mechanism in the integrated process. The hardness reduces while air cooling due to the formation of coarse S precipitates with average size exceeding 750 nm. Finally, a large-size tapered thick plate component with superior dimensional accuracy was successfully fabricated under the guidance of the obtained results.