关键词: 激光冲击, 残余应力, 7050铝合金, 仿真模拟

Abstract: Effect of laser shocking parameters (spot diameter,laser characteristics and peak pressure) on the formation mechanism of residual stress field of 7050 alloy were studied by means of simulation and experiment.The results show that the optimum peak pressure is 1500 MPa when the flat-topped laser is loaded with facula diameter of 2 mm,3 mm and 4 mm.When the Gauss laser is loaded,the optimum peak pressure is 1500 MPa,2000 MPa and 3000 MPa with facula diameter of 2 mm,3 mm and 4 mm,respectively.And the maximum residual stress after the flat-topped laser shock is increased by about 10% than Gauss laser when the peak pressure is 1500 MPa.When the peak pressure is greater than 2000 MPa,affected by surface convergence wave,the maximum residual compressive stress after shocking by flat-topped laser is less than that of Gauss laser.When shocked by the flat-topped laser,the actual optimal solution of peak pressure is consistent with the theoretical optimal solution,which is 1500 MPa.In the case of Gauss laser shocking,the actual optimal solution of peak pressure increases gradually with the increase of the spot diameter.When the peak pressure exceeds 2000 MPa,the residual compressive stress no longer increases significantly,and stress defects such as residual stress holes are more likely to occur.

Key words: laser shocking, residual stress, 7050 aluminum alloy, simulation