Abstract: The mechanical property and bake hardening behavior of two new-type automotive body AA6016 aluminum alloys under different artificial ageing processes are investigated comparatively, and the interrelated micro-mechanism is discussed. The optimal process is as follows：Solution hardening + pre-ageing + natural ageing + artificial ageing (bake hardening), which conduces to strengthening bake hardening. The results indicate that the bake hardening of aluminum alloy is mainly caused by the metastable precipitation of ′′ phase and the dislocations strengthening resulting from pre-deformation. The BH value is insensitive to natural ageing and rolling conditions, which couples with the speed of ′′ phase nucleation. The short-time baking process with high-temperature(2%～3% pre-deformation，170～180 ℃，less than 30 min) contributes to obtaining good bake hardening properties, the yield stress enhances 40～90 MPa. It is a good treatment schedule to promote the bake-hardening and formability of AA6016 aluminum alloys, which has guiding significance to practical application by enterprises.

Key words: AA6016 aluminum alloy, Artificial ageing, Automotive panel, Bake hardening, Process parameter