6061-T6铝合金弧形槽超声冲击处理残余应力场研究

Residual Stress Field of 6061-T6 Aluminum Alloy Arc Groove Induced by Ultrasonic Impact Treatment

研究经超声冲击处理后6061-T6铝合金试件弧形槽表层残余应力场的形成与应力分布特点。借助有限元分析软件,模拟弧形槽经超声冲击处理后残余应力场分布,同时进行正交工艺试验,对比仿真结果,探究不同工艺参数对冲击后弧形槽底面残余应力值的影响规律。结果表明,超声冲击处理在弧形槽底形成了厚度约为0.35mm的残余压应力层,残余应力沿深度方向先增大后减小,最大残余应力值可达约-362.5MPa。工艺试验与相同条件下有限元模拟得到的各工艺参数对槽底表面残余应力值的影响趋势基本一致,弧形槽底面残余应力值随工具振幅的增大而增大,随加工间隙的增加有小幅减小,而工件移动速度的改变则对应力值几乎没有影响。

The work aims to study the formation and stress distribution of the surface residual stress field of the arc groove of6061-T6aluminum alloy specimen after ultrasonic impact treatment.By means of finite element analysis software,the residual stress field distribution of the arc groove is simulated by ultrasonic impact treatment,and the effect of different technological parameters on the residual stress value on the bottom surface of the arc groove is investigated by comparing the simulation results with the orthogonal process test.The results show that the ultrasonic impact treatment has formed a residual compressive stress layer with a thickness of about0.35mm at the bottom of the arc groove,the residual stress first increased and then decreased along the depth direction,and the maximum residual stress value can reach about-362.5MPa.The process test is basically consistent with the influence trend of various process parameters on the residual stress value of the bottom surface of the groove obtained by the finite element simulation under the same condition,the residual stress value at the bottom of the arc groove increases with the increase of tool vibration amplitude,and decreases slightly with the increase of machining gap,while the change of workpiece movement velocity has little effect on the stress value.