Abstract The friction stir welds o thick precipitation-hardenable aluminum alloys suffer from reduced joint strength due to dissolution/coarsening of the strengthening precipitates. The article portray hybrid pin profiled tool that enables sound welds at speeds 7-times faster than a conventional tool (a conical threaded tool), without pin breakage. The conical threaded and triangular cross-section in the upper and lower pin half-lengths of the hybrid tool facilitate material flow in a downward direction and shear deformation at a faster rate, respectively. The paper brings out the process mechanism responsible for the enhanced welding speed and mechanical properties obtainable with the hybrid tool through a case of 13-mm thick aluminum alloy AA2219-T6. The hybrid tool facilitates a 26% improvement in weld strength by reducing TMAZ softening, as evidenced by the microhardness and mechanical properties and supported by microstructural investigation and fractography.

中文翻译：

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混合工具销轮廓对提高 AA2219-T6 搅拌摩擦焊焊接速度和机械性能的作用

摘要 厚沉淀硬化铝合金的搅拌摩擦焊缝由于强化沉淀物的溶解/粗化而导致接头强度降低。这篇文章描述了混合销钉成型工具，它能够以比传统工具（锥形螺纹工具）快 7 倍的速度实现良好的焊接，而不会出现销钉断裂。混合工具的上部和下部销半长中的锥形螺纹和三角形横截面分别促进了材料向下流动和以更快的速度剪切变形。本文通过一个 13 毫米厚的 AA2219-T6 铝合金外壳，揭示了使用混合工具可获得提高焊接速度和机械性能的工艺机制。通过减少 TMAZ 软化，混合工具有助于将焊接强度提高 26%，