利用无针搅拌头,对3.6 mm厚铜镍合金和4 mm厚低碳钢进行搅拌摩擦搭接焊。借助拉剪试验、SEM和EDS,研究焊接参数对接头拉剪强度的影响,并分析多道次焊缝间的最佳间距。结果表明:减小焊接速度或增大预热时间有利于提高接头拉剪强度,试验得到的试样最大拉剪强度达到295 MPa,接近铜镍合金母材的剪断强度。在最佳焊接参数下,多道次焊接需要保证两相邻焊缝间距离小于12 mm,可实现大面积接合面接合。 Using a needleless mixing head, a 3.6 mm thick copper-nickel alloy and a 4 mm thick mild steel are friction stir welded. With the help of tensile shear test, SEM and EDS, the influence of welding parameters on the tensile strength of the joint was studied and the optimal spacing between the multi-pass welds was analyzed. The results show that decreasing the welding speed or increasing the preheating time can improve the tensile strength of the joint. The maximum tensile strength of the specimen reaches 295 MPa, which is close to the shear strength of the base metal of the copper-nickel alloy. Under the optimal welding parameters, multi-pass welding needs to ensure that the distance between two adjacent welds is less than 12 mm, enabling large-area joint engagement.