铝合金搅拌摩擦焊接头残余应力测试分析

Test of residual stresses for the joint of aluminum alloy friction stir welding

采用小孔法研究厚2 mm的6061-T5铝合金搅拌摩擦焊对接接头残余应力的分布规律,分别测量接头处垂直、平行于焊缝的残余应力,并进行了计算分析。结果显示,搅拌摩擦焊接头残余应力在焊缝及其附近区域无论是垂直还是在平行焊缝方向的均承受压应力,且随小孔深度的增加而增加。垂直和平行于焊缝方向的残余应力呈现出周期性分布,且它们在前进侧的周期相比于后退侧较小;残余应力在焊缝两侧呈不对称分布,后退侧应力值较高,其残余应力峰值出现在后退侧轴肩作用区域边缘处,其值分别为93 MPa和100 MPa。

In this paper,the residual stresses for friction stir welded 2 mm thick 6061-T5 aluminum alloy sheets had been investigated by using mathar method.The residual stresses perpendicular and parallel to the weld-path were measure respectively.The results showed that the residual stresses both perpendicular and parallel to the weld-path are all compressive stress,and the value of compressive stress become bigger as the depth of little hole increases.Additionally ,both the compressive stresses are shown periodic distribution,and the periods of advancing side are smaller than the retreating side＇s.The residual stresses of weld joint two sides is not symmetrical,and retreating side residual stresses is higher,which the maximum are 93 MPa and 100 MPa respectively which present to the edge of shoulder.