铝合金静止轴肩搅拌摩擦焊残余应力超声波法测量

Ultrasonic residual stress measurement of stationary shoulder FSW

开发了静止轴肩搅拌摩擦焊装置,在焊接过程中搅拌装置外部轴肩不旋转,内部搅拌针旋转,获得了无弧纹的搅拌摩擦焊缝表面。焊接了6系列铝合金挤压型材和7系列平板对接定轴肩搅拌摩擦焊试件,使用超声波焊接残余应力测量方法对静止轴肩搅拌摩擦焊残余应力场进行了测量。测量结果表明搅拌摩擦焊残余应力最大值可达母材抗拉强度的66%左右,应力峰值不低于弧焊,纵向残余应力最大值产生在焊缝热影响区边界附近,横向残余应力值低于纵向残余应力。

Based on the acoustics-elasticity,the residual stress of stationary shoulder FSW was measured by ultrasonic method.The experiment results show that the longitudinal residual stress is higher tension stress in the vicinity of the weld,but falling rapidly outside the shoulder region.The results also show that the transverse residual stress is smaller in the whole structure.Analysis shows that the residual stress distribution of friction stir welding is caused by the complex material flow and the special welding temperature field.