Refill friction stir spot welding is a new branch of friction stir welding. In this study, the dissimilar Al/Cu joint was acquired by refill friction stir spot welding. A quadratic regression model was established by Box–Behnken design to explore the relationships between the key process parameters of rotational velocity, plunge depth and welding time and the joint tensile shear load. The results show that the rotational velocity is the most dominant factor for tensile shear load, while the welding time and plunge depth are the second and third effective process parameters. The contour map and response surface present that tensile shear load first increases and then decreases with the increase of the investigated process parameters. The maximum tensile shear load of 4.69 kN is acquired at the optimized rotational velocity of 2500 rpm, plunge depth of 1.7 mm and welding time of 6.2 s.

笔芯摩擦搅拌点焊是摩擦搅拌焊的一个新分支。在这项研究中，通过填充摩擦搅拌点焊获得了异种的Al / Cu接头。通过Box-Behnken设计建立了二次回归模型，以探讨关键工艺参数转速，切入深度和焊接时间与接头拉伸剪切载荷之间的关系。结果表明，旋转速度是拉伸剪切载荷的最主要因素，而焊接时间和切入深度是第二和第三有效工艺参数。轮廓图和响应面表明，随着所研究工艺参数的增加，拉伸剪切载荷首先增大，然后减小。在2500 rpm的最佳转速下可获得4.69 kN的最大拉伸剪切负荷，