焊接位置对5083铝合金搅拌摩擦焊T形接头性能的影响

Influence of welding position on properties of 5083 aluminum alloy T-joints by friction stir welding

通过调整搅拌工具焊接位置与增加预焊工序的方法对5083铝合金T形接头进行了搅拌摩擦焊对接试验,对焊缝横截面进行了金相组织观测,对接头进行了拉伸、弯曲检测并对断口进行扫面电镜检测。结果表明,传统焊接的T形接头在根部易产生裂纹缺陷,调整焊接位置并增加焊接深度的方法可以消除裂纹缺陷,但同时导致根部轻微变形,通过增加一次预焊的工序可以消除根部变形;"调整焊接位置+预焊"后的接头抗拉强度、屈服强度、断口伸长率分别提升32.5%,32.1%和71.4%;工艺改进后的试样弯曲检测裂纹的弯曲程度降低,断口韧窝的尺寸增大,断裂机制向韧性断裂方向发展。

Friction stir welding butt test of 5083 aluminum alloy T-joint was carried out by adjusting the welding position of tool and adding pre-welding procedure.The metallographic structure of the cross section of the weld was observed,the tensile and bending of the joint were detected,and the fracture was detected by scanning electron microscopy.The results showed that the traditional welded T-joints were prone to crack at the root,which could be eliminated by adjusting the welding position and increasing the welding depth,but it also caused the root to deform slightly,which could be eliminated by adding a pre-welding procedure.The tensile strength,yield strength and elongation at fracture of joints increased by 32.5%,32.1%and 71.4%respectively after"adjusting welding position+pre-welding".After process improvement,the bending degree of specimen after bending detection flattened,the size of fracture dimple increased,and the fracture mechanism developed to the direction of ductile fracture.