回填式搅拌摩擦点焊(refill friction stir spot welding, RFSSW)凭借其效率高、质量好的优势，在轻质高强铝合金连接领域已展现出广阔的应用前景。 然而，目前针对异种材料的 RFSSW 研究尚不充分，缺乏完善的接头质量评价体系。 本研究以 2B06/7B04 高强铝合金异种组配为研究对象，通过系统的 RFSSW 工艺试验，获得了工艺参数与接头形貌特征、显微硬度分布及拉剪性能之间的关系，实现了焊接工艺优化。 通过拟合回归方程获得的最佳工艺参数为：转速1600 r/min、下压量 1.47 mm、下压速率 60 mm/min，在此参数下接头的拉剪失效载荷达到了 5.22 kN。 通过对拉剪断口形貌分析，发现接头有两种断裂模式：塞型断裂与混合型断裂，其中塞型断裂的失效载荷低于混合型断裂。

Refill friction stir spot welding (RFSSW) has demonstrated broad application prospects in the field of lightweight, high-strength aluminium alloys because of its advantages of high efficiency and superior quality. However, studies on RFSSW for dissimilar materials have not been sufficiently conducted, and a comprehensive evaluation system for joint quality is still lacking. This study focused on the dissimilar combination of 2B06/7B04 high-strength aluminium alloys. Through systematic RFSSW process experiments, relationships between the welding parameters and joint morphology characteristics, microhardness distribution, and tensile-shear properties were established, ultimately achieving process optimization. The optimal process parameters obtained by fitting the regression equation are as follows: rotational speed, 1 600 r/min; press volume, 1.47 mm; press rate, 60 mm/min; and refill rate, 60 mm/min. The corresponding joint tensile-shear failure load is 5.22 kN. The analysis of tensile-shear fracture morphology reveals that the joints exhibit two fracture modes, plug-type fracture and mixed-mode fracture, whereby the failure load of plug-type fracture was lower than that of mixed-mode fracture.