Refill Friction Stir Spot Welding (RFSSW) has demonstrated capability in joining thin sheets of aluminum with dissimilar thickness, alloy, and composition. The process remains to be implemented on a wide scale in the automotive and aerospace industries, partially due to the relatively short number of welds producible by a toolset, prior to needing cleaning. In the following work, an investigation was conducted to better understand this limitation. First, the effective tool life of a steel toolset was quantified. Experiments showed that less than 60 consecutive welds could be made before the toolset seized and required cleaning. To better understand the conditions contributing so such a short tool life, thermocouples were used in subsequent experiments, to measure the temperatures achieved at various locations in the weld. Peak weld temperature increased with longer cycle times and decreased with shorter cycle times. During the experiments, it was noted that weld temperatures in excess of 500 °C were observed at weld center. At these high temperatures, the authors anticipate that intermetallic compounds (IMCs) are able to grow on tool surfaces. A rough, existing model of IMC growth in an Fe-Al system predicted IMC growth on the same order of magnitude of the tool clearances, supporting the anticipation that IMC growth is a factor in the observed, short tool life between cleanings. Following this analysis, future evaluation of less re-active tool materials is recommended.

补充摩擦搅拌点焊（RFSSW）已证明能够连接厚度，合金和成分不同的铝薄板。该过程仍有待在汽车和航空航天工业中大规模实施，部分原因是在需要清洁之前，工具箱可生产的焊缝数量相对较少。在以下工作中，进行了调查以更好地理解此限制。首先，对钢制工具组的有效工具寿命进行了量化。实验表明，在扣住工具包并需要清洁之前，可以进行少于60次的连续焊接。为了更好地了解造成如此短工具寿命的条件，在随后的实验中使用了热电偶，以测量在焊缝中各个位置所达到的温度。峰值焊接温度随着循环时间的延长而增加，而随着循环时间的缩短而降低。在实验过程中，应注意在焊接中心观察到的焊接温度超过500°C。在这些高温下，作者预计金属间化合物（IMC）能够在工具表面生长。在Fe-Al系统中，IMC生长的现有粗略模型预测工具间隙相同数量级上的IMC增长，从而支持了以下预期：IMC的增长是观察到的两次清洁之间工具寿命短的一个因素。经过此分析后，建议对反应性较低的工具材料进行进一步评估。在这些高温下，作者预计金属间化合物（IMC）能够在工具表面生长。在Fe-Al系统中，IMC生长的现有粗略模型预测了工具间隙相同数量级上的IMC增长，这支持了以下预期：IMC增长是观察到的两次清洁之间工具寿命短的一个因素。经过此分析后，建议对反应性较低的工具材料进行进一步评估。在这些高温下，作者预计金属间化合物（IMC）能够在工具表面生长。在Fe-Al系统中，IMC生长的现有粗略模型预测了工具间隙相同数量级上的IMC增长，从而支持了以下预期：IMC的增长是观察到的两次清洁之间工具寿命短的一个因素。经过此分析后，建议对反应性较低的工具材料进行进一步评估。