Abstract:As aircraft is the main object of laser weapon, it is necessary to research on response of aeronautical materials under laser irradiation. In this work, experiments and finite element simulation were applied to investigate ablation characters of 1080nm continuous laser on LY12-CZ aluminum alloy under pre-stressed loading. The experiment results show that three kinds of microstructure exist in the remaining target material after laser ablation, namely dendrite, equiaxed grain and primitive microstructure. Element segregation among grain boundaries present in dendrite and equiaxed grain structures. High internal stress exists in the dendrite structure. The finite element simulation results show that the temperature field is not sensitive to the applied pre-stress. One of the reasons for the formation of burn-through hole is the local yield caused by hot softening and high level thermal stress. Compared with thermal stress, pre-stress is not easy to reach the yield strength which is decreased by the increasing temperature.