The effects of rotation speed and plunge depth on macro/microstructures and mechanical properties of dissimilar 2195/2219 aluminum alloy joints produced by refill friction stir spot welding (RFSSW) were investigated. The results show that some shallow annular grooves present on the joint surfaces depending on the process parameters. Besides, hook defects are in the form of downward bending due to the higher strength of 2195 aluminum alloy. The change of rotating speed has no apparent influence on hook defect, while the increase of plunge depth makes the height of the hook defect increase significantly. The higher tensile-shear strength is associated with increased rotation speed. However, as the plunge depth increases, the tensile-shear strength rises first and then decreases. The highest tensile-shear strength measured is 6480 N, for a rotation speed of 1600 rpm, and plunge depth of 2.5 mm. Besides, there are two kinds of fracture modes present: the plug fracture and the shear-plug fracture.

研究了旋转速度和切入深度对通过填充摩擦搅拌点焊（RFSSW）制成的不同的2195/2219铝合金接头的宏观/微观结构和力学性能的影响。结果表明，取决于工艺参数，在接合面上存在一些浅环形槽。此外，由于2195铝合金强度更高，钩子缺陷呈向下弯曲的形式。转速的变化对钩缺陷没有明显影响，而切入深度的增加使钩缺陷的高度明显增加。较高的拉伸剪切强度与转速增加相关。但是，随着切入深度的增加，拉伸剪切强度会先上升然后下降。测得的最高拉伸剪切强度为6480 N，转速为1600 rpm，切入深度为2.5 mm。此外，还存在两种断​​裂模式：塞子断裂和剪切塞子断裂。