2219铝合金搅拌摩擦焊和钨极保护焊焊接件残余应力的中子衍射研究

利用中子衍射法对2219铝合金搅拌摩擦焊（FSW）和钨极保护焊（TIG）焊接件开展了三维残余应力测量，并对残余应力分布规律进行了分析。结果表明：焊接件的纵向残余应力数值较大；FSW焊接件残余应力整体较TIG焊接件的小；FSW和TIG焊接件的残余拉应力最大值分别为101 MPa和174 MPa，FSW焊接件残余拉应力最大值较TIG焊接件的小；FSW残余拉应力最大值处于轴肩边缘，且前进侧峰值大于后退侧峰值；TIG焊接件残余拉应力最大值处于焊缝边缘。通过中子衍射实验获得的焊接件残余应力分布，将可用于焊接工艺的优化与焊接件的寿命预测。

Study on Residual Stress in Friction Stir and Tungsten Inert Gas Welded 2219 Aluminum Alloy Sheets Using Neutron Diffraction

The 3D residual stresses in the friction stir and tungsten inert gas welded 2219 aluminum alloy sheets were characterized using neutron diffraction. The results show that residual stress is larger in longitudinal direction after welding process. The magnitude of the residual stress in friction stir welded sheet is generally smaller than that in the tungsten inert gas welded sheet. The maximum tensile stress of friction stir welded sheet is 101 MPa, which is smaller than that of tungsten inert gas welded stress of 174 MPa. Friction stir welded sheet tensile peaks show at sides of the tool edge, and the tensile residual stress on the advancing side is higher than that on the retreating side. Tungsten inert gas welded stress residual stress peaks show at the sides of welding zone. Residual stress distributions obtained by neutron diffraction will be used to optimize the welding process and predict the lifespan of 2219 aluminum alloy.