2024铝合金搅拌摩擦焊残余应力分布研究

摘要

采用9组不同的焊接参数，利用分割释放法对3.2mm厚2024-T3铝合金板搅拌摩擦焊对接板进行了上下两表面纵向残余应力的测量，然后对其分布规律进行了分析研究。结果表明，上表面的纵向残余应力呈现双峰值，峰值出现在轴肩两侧边缘，不对称分布，前进侧残余拉应力普遍高于后退侧；下表面呈现单峰值，峰值出现在焊缝中心附近，靠近前进侧；下表面的纵向残余应力峰值普遍高于上表面；上下两表面的纵向残余应力峰值会随着转速的增加或者焊速的减小而减小，即会随着热输入量的增加而减小。%2024-T3 aluminum alloy sheet with 3.2mm in thickness is friction stir welded in 9 different parameters, and the upper and lower longitudinal surface residual stresses are measured by using cutting-release method. The results show that the longitudinal residual stress on the upper surface presents double-peak, and the two peaks distribute asymmetric in the two sides of the edge. The tensile residual stress on the advancing side is generally higher than that on the retreating side. The re-sidual stress on the lower surface presents single peak, and the peak appears near the center of the weld, close to the advancing side. The peak longitudinal residual stress on the lower side is generally higher than that on the upper surface. The peak residual stress on the upper and lower surfaces will decrease as the welding speed decreases or the rotation speed increases, in other words, the peak re-sidual stress will decrease as the heat-input increases.