Abstract: By introducing the flow stress curve, the numerical simulation of stress redistribution during the quenching process for 7075 aluminum alloy plates with different thickness is performed using a direct thermo-mechanical coupled method. Considering the practical clamping, the stretching simulation of 7075 aluminum alloy sheets with different thickness is conducted to analyze the residual stress distribution. Also, the pre-stretching process is optimized to determine the stretch rate and the amount of cutting. Through the analysis, the influences of thickness variation on quenching-induced residual stresses, stretching residual stresses and the amount of cutting are investigated. A practical experiment was conducted to demonstrate the quenching-induced residual stresses distribution using a blind hole measuring method. The result which compares well with the simulation shows that the quenching-induced residual stress, stretch rate and the amount of cutting are increased as the aluminium alloy plate becomes thicker. The length of transition zone is about 60%～70 % of the thickness.

Key words: Amount of cutting, Pre-stretching, Quenching, Residual stress, Thickness variation