In this study, a new method was proposed to reduce the keyhole volume with friction stir spot welding process and improve the lap joint shear load-carrying capacity of the weld by analyzing the effects of tool rotation speed, plunge depth and dwell time on the weld. Single lap shear tests were carried out to determine the influences of the welding parameters on the mechanical behavior of the welds. The quality of the joint was evaluated by examining the characteristics of the joint as a result of the lap joint shear load. For friction stir spot welding of the acrylonitrile butadiene styrene samples, the experiments were designed according to Taguchi’s L9 orthogonal array in a randomized way. From the analysis of variance and the signal-to-noise ratio, the significant parameters and the optimum combination level of the parameters were obtained. It was found that using a tool rotation of 1000 rpm, plunge depth 11.5 mm and dwell time of 40 s, an improved joint strength can be obtained. The results showed that joint strength was improved by an amount of 20% as compared with the optimum welding parameters to the initial welding parameters. Macrostructure examination plays an important role to determine the joint strength and evaluate the influences of each welding parameters. So, weld morphology was investigated by morphological analysis and visual comparisons. It was also observed failure modes for fractured samples having the highest, moderate and lowest lap joint shear load.

通过研究工具旋转速度，切入深度和停留时间对焊缝的影响，提出了一种通过搅拌摩擦点焊减少键孔体积并提高搭接接头剪切承载能力的新方法。 。进行单搭接剪切试验以确定焊接参数对焊接机械性能的影响。通过检查搭接接头剪切载荷的结果来评估接头的质量。对于丙烯腈-丁二烯-苯乙烯样品的摩擦搅拌点焊，根据Taguchi的L9正交阵列以随机方式设计实验。通过方差和信噪比的分析，获得了重要的参数和参数的最佳组合水平。已经发现，使用工具旋转速度为1000 rpm，切入深度为11.5 mm，停留时间为40 s，可以获得更高的接头强度。结果表明，与最佳焊接参数相比，初始焊接参数的接头强度提高了20％。宏观结构检查在确定接头强度和评估每个焊接参数的影响方面起着重要作用。因此，通过形态分析和视觉比较研究了焊接形态。还观察到具有最高，中度和最低搭接接头剪切载荷的破裂样品的破坏模式。结果表明，与最佳焊接参数相比，初始焊接参数的接头强度提高了20％。宏观结构检查在确定接头强度和评估每个焊接参数的影响方面起着重要作用。因此，通过形态分析和视觉比较研究了焊接形态。还观察到具有最高，中度和最低搭接接头剪切载荷的破裂样品的破坏模式。结果表明，与最佳焊接参数相比，初始焊接参数的接头强度提高了20％。宏观结构检查在确定接头强度和评估每个焊接参数的影响方面起着重要作用。因此，通过形态分析和视觉比较研究了焊接形态。还观察到具有最高，中度和最低搭接接头剪切载荷的破裂样品的破坏模式。